/*  Prototype JavaScript framework, version 1.6.0.2

 *  (c) 2005-2008 Sam Stephenson

 *

 *  Prototype is freely distributable under the terms of an MIT-style license.

 *  For details, see the Prototype web site: http://www.prototypejs.org/

 *

 *--------------------------------------------------------------------------*/



var Prototype = {

  Version: '1.6.0.2',



  Browser: {

    IE:     !!(window.attachEvent && !window.opera),

    Opera:  !!window.opera,

    WebKit: navigator.userAgent.indexOf('AppleWebKit/') > -1,

    Gecko:  navigator.userAgent.indexOf('Gecko') > -1 && navigator.userAgent.indexOf('KHTML') == -1,

    MobileSafari: !!navigator.userAgent.match(/Apple.*Mobile.*Safari/)

  },



  BrowserFeatures: {

    XPath: !!document.evaluate,

    ElementExtensions: !!window.HTMLElement,

    SpecificElementExtensions:

      document.createElement('div').__proto__ &&

      document.createElement('div').__proto__ !==

        document.createElement('form').__proto__

  },



  ScriptFragment: '<script[^>]*>([\\S\\s]*?)<\/script>',

  JSONFilter: /^\/\*-secure-([\s\S]*)\*\/\s*$/,



  emptyFunction: function() { },

  K: function(x) { return x }

};



if (Prototype.Browser.MobileSafari)

  Prototype.BrowserFeatures.SpecificElementExtensions = false;





/* Based on Alex Arnell's inheritance implementation. */

var Class = {

  create: function() {

    var parent = null, properties = $A(arguments);

    if (Object.isFunction(properties[0]))

      parent = properties.shift();



    function klass() {

      this.initialize.apply(this, arguments);

    }



    Object.extend(klass, Class.Methods);

    klass.superclass = parent;

    klass.subclasses = [];



    if (parent) {

      var subclass = function() { };

      subclass.prototype = parent.prototype;

      klass.prototype = new subclass;

      parent.subclasses.push(klass);

    }



    for (var i = 0; i < properties.length; i++)

      klass.addMethods(properties[i]);



    if (!klass.prototype.initialize)

      klass.prototype.initialize = Prototype.emptyFunction;



    klass.prototype.constructor = klass;



    return klass;

  }

};



Class.Methods = {

  addMethods: function(source) {

    var ancestor   = this.superclass && this.superclass.prototype;

    var properties = Object.keys(source);



    if (!Object.keys({ toString: true }).length)

      properties.push("toString", "valueOf");



    for (var i = 0, length = properties.length; i < length; i++) {

      var property = properties[i], value = source[property];

      if (ancestor && Object.isFunction(value) &&

          value.argumentNames().first() == "$super") {

        var method = value, value = Object.extend((function(m) {

          return function() { return ancestor[m].apply(this, arguments) };

        })(property).wrap(method), {

          valueOf:  function() { return method },

          toString: function() { return method.toString() }

        });

      }

      this.prototype[property] = value;

    }



    return this;

  }

};



var Abstract = { };



Object.extend = function(destination, source) {

  for (var property in source)

    destination[property] = source[property];

  return destination;

};



Object.extend(Object, {

  inspect: function(object) {

    try {

      if (Object.isUndefined(object)) return 'undefined';

      if (object === null) return 'null';

      return object.inspect ? object.inspect() : String(object);

    } catch (e) {

      if (e instanceof RangeError) return '...';

      throw e;

    }

  },



  toJSON: function(object) {

    var type = typeof object;

    switch (type) {

      case 'undefined':

      case 'function':

      case 'unknown': return;

      case 'boolean': return object.toString();

    }



    if (object === null) return 'null';

    if (object.toJSON) return object.toJSON();

    if (Object.isElement(object)) return;



    var results = [];

    for (var property in object) {

      var value = Object.toJSON(object[property]);

      if (!Object.isUndefined(value))

        results.push(property.toJSON() + ': ' + value);

    }



    return '{' + results.join(', ') + '}';

  },



  toQueryString: function(object) {

    return $H(object).toQueryString();

  },



  toHTML: function(object) {

    return object && object.toHTML ? object.toHTML() : String.interpret(object);

  },



  keys: function(object) {

    var keys = [];

    for (var property in object)

      keys.push(property);

    return keys;

  },



  values: function(object) {

    var values = [];

    for (var property in object)

      values.push(object[property]);

    return values;

  },



  clone: function(object) {

    return Object.extend({ }, object);

  },



  isElement: function(object) {

    return object && object.nodeType == 1;

  },



  isArray: function(object) {

    return object != null && typeof object == "object" &&

      'splice' in object && 'join' in object;

  },



  isHash: function(object) {

    return object instanceof Hash;

  },



  isFunction: function(object) {

    return typeof object == "function";

  },



  isString: function(object) {

    return typeof object == "string";

  },



  isNumber: function(object) {

    return typeof object == "number";

  },



  isUndefined: function(object) {

    return typeof object == "undefined";

  }

});



Object.extend(Function.prototype, {

  argumentNames: function() {

    var names = this.toString().match(/^[\s\(]*function[^(]*\((.*?)\)/)[1].split(",").invoke("strip");

    return names.length == 1 && !names[0] ? [] : names;

  },



  bind: function() {

    if (arguments.length < 2 && Object.isUndefined(arguments[0])) return this;

    var __method = this, args = $A(arguments), object = args.shift();

    return function() {

      return __method.apply(object, args.concat($A(arguments)));

    }

  },



  bindAsEventListener: function() {

    var __method = this, args = $A(arguments), object = args.shift();

    return function(event) {

      return __method.apply(object, [event || window.event].concat(args));

    }

  },



  curry: function() {

    if (!arguments.length) return this;

    var __method = this, args = $A(arguments);

    return function() {

      return __method.apply(this, args.concat($A(arguments)));

    }

  },



  delay: function() {

    var __method = this, args = $A(arguments), timeout = args.shift() * 1000;

    return window.setTimeout(function() {

      return __method.apply(__method, args);

    }, timeout);

  },



  wrap: function(wrapper) {

    var __method = this;

    return function() {

      return wrapper.apply(this, [__method.bind(this)].concat($A(arguments)));

    }

  },



  methodize: function() {

    if (this._methodized) return this._methodized;

    var __method = this;

    return this._methodized = function() {

      return __method.apply(null, [this].concat($A(arguments)));

    };

  }

});



Function.prototype.defer = Function.prototype.delay.curry(0.01);



Date.prototype.toJSON = function() {

  return '"' + this.getUTCFullYear() + '-' +

    (this.getUTCMonth() + 1).toPaddedString(2) + '-' +

    this.getUTCDate().toPaddedString(2) + 'T' +

    this.getUTCHours().toPaddedString(2) + ':' +

    this.getUTCMinutes().toPaddedString(2) + ':' +

    this.getUTCSeconds().toPaddedString(2) + 'Z"';

};



var Try = {

  these: function() {

    var returnValue;



    for (var i = 0, length = arguments.length; i < length; i++) {

      var lambda = arguments[i];

      try {

        returnValue = lambda();

        break;

      } catch (e) { }

    }



    return returnValue;

  }

};



RegExp.prototype.match = RegExp.prototype.test;



RegExp.escape = function(str) {

  return String(str).replace(/([.*+?^=!:${}()|[\]\/\\])/g, '\\$1');

};



/*--------------------------------------------------------------------------*/



var PeriodicalExecuter = Class.create({

  initialize: function(callback, frequency) {

    this.callback = callback;

    this.frequency = frequency;

    this.currentlyExecuting = false;



    this.registerCallback();

  },



  registerCallback: function() {

    this.timer = setInterval(this.onTimerEvent.bind(this), this.frequency * 1000);

  },



  execute: function() {

    this.callback(this);

  },



  stop: function() {

    if (!this.timer) return;

    clearInterval(this.timer);

    this.timer = null;

  },



  onTimerEvent: function() {

    if (!this.currentlyExecuting) {

      try {

        this.currentlyExecuting = true;

        this.execute();

      } finally {

        this.currentlyExecuting = false;

      }

    }

  }

});

Object.extend(String, {

  interpret: function(value) {

    return value == null ? '' : String(value);

  },

  specialChar: {

    '\b': '\\b',

    '\t': '\\t',

    '\n': '\\n',

    '\f': '\\f',

    '\r': '\\r',

    '\\': '\\\\'

  }

});



Object.extend(String.prototype, {

  gsub: function(pattern, replacement) {

    var result = '', source = this, match;

    replacement = arguments.callee.prepareReplacement(replacement);



    while (source.length > 0) {

      if (match = source.match(pattern)) {

        result += source.slice(0, match.index);

        result += String.interpret(replacement(match));

        source  = source.slice(match.index + match[0].length);

      } else {

        result += source, source = '';

      }

    }

    return result;

  },



  sub: function(pattern, replacement, count) {

    replacement = this.gsub.prepareReplacement(replacement);

    count = Object.isUndefined(count) ? 1 : count;



    return this.gsub(pattern, function(match) {

      if (--count < 0) return match[0];

      return replacement(match);

    });

  },



  scan: function(pattern, iterator) {

    this.gsub(pattern, iterator);

    return String(this);

  },



  truncate: function(length, truncation) {

    length = length || 30;

    truncation = Object.isUndefined(truncation) ? '...' : truncation;

    return this.length > length ?

      this.slice(0, length - truncation.length) + truncation : String(this);

  },



  strip: function() {

    return this.replace(/^\s+/, '').replace(/\s+$/, '');

  },



  stripTags: function() {

    return this.replace(/<\/?[^>]+>/gi, '');

  },



  stripScripts: function() {

    return this.replace(new RegExp(Prototype.ScriptFragment, 'img'), '');

  },



  extractScripts: function() {

    var matchAll = new RegExp(Prototype.ScriptFragment, 'img');

    var matchOne = new RegExp(Prototype.ScriptFragment, 'im');

    return (this.match(matchAll) || []).map(function(scriptTag) {

      return (scriptTag.match(matchOne) || ['', ''])[1];

    });

  },



  evalScripts: function() {

    return this.extractScripts().map(function(script) { return eval(script) });

  },



  escapeHTML: function() {

    var self = arguments.callee;

    self.text.data = this;

    return self.div.innerHTML;

  },



  unescapeHTML: function() {

    var div = new Element('div');

    div.innerHTML = this.stripTags();

    return div.childNodes[0] ? (div.childNodes.length > 1 ?

      $A(div.childNodes).inject('', function(memo, node) { return memo+node.nodeValue }) :

      div.childNodes[0].nodeValue) : '';

  },



  toQueryParams: function(separator) {

    var match = this.strip().match(/([^?#]*)(#.*)?$/);

    if (!match) return { };



    return match[1].split(separator || '&').inject({ }, function(hash, pair) {

      if ((pair = pair.split('='))[0]) {

        var key = decodeURIComponent(pair.shift());

        var value = pair.length > 1 ? pair.join('=') : pair[0];

        if (value != undefined) value = decodeURIComponent(value);



        if (key in hash) {

          if (!Object.isArray(hash[key])) hash[key] = [hash[key]];

          hash[key].push(value);

        }

        else hash[key] = value;

      }

      return hash;

    });

  },



  toArray: function() {

    return this.split('');

  },



  succ: function() {

    return this.slice(0, this.length - 1) +

      String.fromCharCode(this.charCodeAt(this.length - 1) + 1);

  },



  times: function(count) {

    return count < 1 ? '' : new Array(count + 1).join(this);

  },



  camelize: function() {

    var parts = this.split('-'), len = parts.length;

    if (len == 1) return parts[0];



    var camelized = this.charAt(0) == '-'

      ? parts[0].charAt(0).toUpperCase() + parts[0].substring(1)

      : parts[0];



    for (var i = 1; i < len; i++)

      camelized += parts[i].charAt(0).toUpperCase() + parts[i].substring(1);



    return camelized;

  },



  capitalize: function() {

    return this.charAt(0).toUpperCase() + this.substring(1).toLowerCase();

  },



  underscore: function() {

    return this.gsub(/::/, '/').gsub(/([A-Z]+)([A-Z][a-z])/,'#{1}_#{2}').gsub(/([a-z\d])([A-Z])/,'#{1}_#{2}').gsub(/-/,'_').toLowerCase();

  },



  dasherize: function() {

    return this.gsub(/_/,'-');

  },



  inspect: function(useDoubleQuotes) {

    var escapedString = this.gsub(/[\x00-\x1f\\]/, function(match) {

      var character = String.specialChar[match[0]];

      return character ? character : '\\u00' + match[0].charCodeAt().toPaddedString(2, 16);

    });

    if (useDoubleQuotes) return '"' + escapedString.replace(/"/g, '\\"') + '"';

    return "'" + escapedString.replace(/'/g, '\\\'') + "'";

  },



  toJSON: function() {

    return this.inspect(true);

  },



  unfilterJSON: function(filter) {

    return this.sub(filter || Prototype.JSONFilter, '#{1}');

  },



  isJSON: function() {

    var str = this;

    if (str.blank()) return false;

    str = this.replace(/\\./g, '@').replace(/"[^"\\\n\r]*"/g, '');

    return (/^[,:{}\[\]0-9.\-+Eaeflnr-u \n\r\t]*$/).test(str);

  },



  evalJSON: function(sanitize) {

    var json = this.unfilterJSON();

    try {

      if (!sanitize || json.isJSON()) return eval('(' + json + ')');

    } catch (e) { }

    throw new SyntaxError('Badly formed JSON string: ' + this.inspect());

  },



  include: function(pattern) {

    return this.indexOf(pattern) > -1;

  },



  startsWith: function(pattern) {

    return this.indexOf(pattern) === 0;

  },



  endsWith: function(pattern) {

    var d = this.length - pattern.length;

    return d >= 0 && this.lastIndexOf(pattern) === d;

  },



  empty: function() {

    return this == '';

  },



  blank: function() {

    return /^\s*$/.test(this);

  },



  interpolate: function(object, pattern) {

    return new Template(this, pattern).evaluate(object);

  }

});



if (Prototype.Browser.WebKit || Prototype.Browser.IE) Object.extend(String.prototype, {

  escapeHTML: function() {

    return this.replace(/&/g,'&amp;').replace(/</g,'&lt;').replace(/>/g,'&gt;');

  },

  unescapeHTML: function() {

    return this.replace(/&amp;/g,'&').replace(/&lt;/g,'<').replace(/&gt;/g,'>');

  }

});



String.prototype.gsub.prepareReplacement = function(replacement) {

  if (Object.isFunction(replacement)) return replacement;

  var template = new Template(replacement);

  return function(match) { return template.evaluate(match) };

};



String.prototype.parseQuery = String.prototype.toQueryParams;



Object.extend(String.prototype.escapeHTML, {

  div:  document.createElement('div'),

  text: document.createTextNode('')

});



with (String.prototype.escapeHTML) div.appendChild(text);



var Template = Class.create({

  initialize: function(template, pattern) {

    this.template = template.toString();

    this.pattern = pattern || Template.Pattern;

  },



  evaluate: function(object) {

    if (Object.isFunction(object.toTemplateReplacements))

      object = object.toTemplateReplacements();



    return this.template.gsub(this.pattern, function(match) {

      if (object == null) return '';



      var before = match[1] || '';

      if (before == '\\') return match[2];



      var ctx = object, expr = match[3];

      var pattern = /^([^.[]+|\[((?:.*?[^\\])?)\])(\.|\[|$)/;

      match = pattern.exec(expr);

      if (match == null) return before;



      while (match != null) {

        var comp = match[1].startsWith('[') ? match[2].gsub('\\\\]', ']') : match[1];

        ctx = ctx[comp];

        if (null == ctx || '' == match[3]) break;

        expr = expr.substring('[' == match[3] ? match[1].length : match[0].length);

        match = pattern.exec(expr);

      }



      return before + String.interpret(ctx);

    });

  }

});

Template.Pattern = /(^|.|\r|\n)(#\{(.*?)\})/;



var $break = { };



var Enumerable = {

  each: function(iterator, context) {

    var index = 0;

    iterator = iterator.bind(context);

    try {

      this._each(function(value) {

        iterator(value, index++);

      });

    } catch (e) {

      if (e != $break) throw e;

    }

    return this;

  },



  eachSlice: function(number, iterator, context) {

    iterator = iterator ? iterator.bind(context) : Prototype.K;

    var index = -number, slices = [], array = this.toArray();

    while ((index += number) < array.length)

      slices.push(array.slice(index, index+number));

    return slices.collect(iterator, context);

  },



  all: function(iterator, context) {

    iterator = iterator ? iterator.bind(context) : Prototype.K;

    var result = true;

    this.each(function(value, index) {

      result = result && !!iterator(value, index);

      if (!result) throw $break;

    });

    return result;

  },



  any: function(iterator, context) {

    iterator = iterator ? iterator.bind(context) : Prototype.K;

    var result = false;

    this.each(function(value, index) {

      if (result = !!iterator(value, index))

        throw $break;

    });

    return result;

  },



  collect: function(iterator, context) {

    iterator = iterator ? iterator.bind(context) : Prototype.K;

    var results = [];

    this.each(function(value, index) {

      results.push(iterator(value, index));

    });

    return results;

  },



  detect: function(iterator, context) {

    iterator = iterator.bind(context);

    var result;

    this.each(function(value, index) {

      if (iterator(value, index)) {

        result = value;

        throw $break;

      }

    });

    return result;

  },



  findAll: function(iterator, context) {

    iterator = iterator.bind(context);

    var results = [];

    this.each(function(value, index) {

      if (iterator(value, index))

        results.push(value);

    });

    return results;

  },



  grep: function(filter, iterator, context) {

    iterator = iterator ? iterator.bind(context) : Prototype.K;

    var results = [];



    if (Object.isString(filter))

      filter = new RegExp(filter);



    this.each(function(value, index) {

      if (filter.match(value))

        results.push(iterator(value, index));

    });

    return results;

  },



  include: function(object) {

    if (Object.isFunction(this.indexOf))

      if (this.indexOf(object) != -1) return true;



    var found = false;

    this.each(function(value) {

      if (value == object) {

        found = true;

        throw $break;

      }

    });

    return found;

  },



  inGroupsOf: function(number, fillWith) {

    fillWith = Object.isUndefined(fillWith) ? null : fillWith;

    return this.eachSlice(number, function(slice) {

      while(slice.length < number) slice.push(fillWith);

      return slice;

    });

  },



  inject: function(memo, iterator, context) {

    iterator = iterator.bind(context);

    this.each(function(value, index) {

      memo = iterator(memo, value, index);

    });

    return memo;

  },



  invoke: function(method) {

    var args = $A(arguments).slice(1);

    return this.map(function(value) {

      return value[method].apply(value, args);

    });

  },



  max: function(iterator, context) {

    iterator = iterator ? iterator.bind(context) : Prototype.K;

    var result;

    this.each(function(value, index) {

      value = iterator(value, index);

      if (result == null || value >= result)

        result = value;

    });

    return result;

  },



  min: function(iterator, context) {

    iterator = iterator ? iterator.bind(context) : Prototype.K;

    var result;

    this.each(function(value, index) {

      value = iterator(value, index);

      if (result == null || value < result)

        result = value;

    });

    return result;

  },



  partition: function(iterator, context) {

    iterator = iterator ? iterator.bind(context) : Prototype.K;

    var trues = [], falses = [];

    this.each(function(value, index) {

      (iterator(value, index) ?

        trues : falses).push(value);

    });

    return [trues, falses];

  },



  pluck: function(property) {

    var results = [];

    this.each(function(value) {

      results.push(value[property]);

    });

    return results;

  },



  reject: function(iterator, context) {

    iterator = iterator.bind(context);

    var results = [];

    this.each(function(value, index) {

      if (!iterator(value, index))

        results.push(value);

    });

    return results;

  },



  sortBy: function(iterator, context) {

    iterator = iterator.bind(context);

    return this.map(function(value, index) {

      return {value: value, criteria: iterator(value, index)};

    }).sort(function(left, right) {

      var a = left.criteria, b = right.criteria;

      return a < b ? -1 : a > b ? 1 : 0;

    }).pluck('value');

  },



  toArray: function() {

    return this.map();

  },



  zip: function() {

    var iterator = Prototype.K, args = $A(arguments);

    if (Object.isFunction(args.last()))

      iterator = args.pop();



    var collections = [this].concat(args).map($A);

    return this.map(function(value, index) {

      return iterator(collections.pluck(index));

    });

  },



  size: function() {

    return this.toArray().length;

  },



  inspect: function() {

    return '#<Enumerable:' + this.toArray().inspect() + '>';

  }

};



Object.extend(Enumerable, {

  map:     Enumerable.collect,

  find:    Enumerable.detect,

  select:  Enumerable.findAll,

  filter:  Enumerable.findAll,

  member:  Enumerable.include,

  entries: Enumerable.toArray,

  every:   Enumerable.all,

  some:    Enumerable.any

});

function $A(iterable) {

  if (!iterable) return [];

  if (iterable.toArray) return iterable.toArray();

  var length = iterable.length || 0, results = new Array(length);

  while (length--) results[length] = iterable[length];

  return results;

}



if (Prototype.Browser.WebKit) {

  $A = function(iterable) {

    if (!iterable) return [];

    if (!(Object.isFunction(iterable) && iterable == '[object NodeList]') &&

        iterable.toArray) return iterable.toArray();

    var length = iterable.length || 0, results = new Array(length);

    while (length--) results[length] = iterable[length];

    return results;

  };

}



Array.from = $A;



Object.extend(Array.prototype, Enumerable);



if (!Array.prototype._reverse) Array.prototype._reverse = Array.prototype.reverse;



Object.extend(Array.prototype, {

  _each: function(iterator) {

    for (var i = 0, length = this.length; i < length; i++)

      iterator(this[i]);

  },



  clear: function() {

    this.length = 0;

    return this;

  },



  first: function() {

    return this[0];

  },



  last: function() {

    return this[this.length - 1];

  },



  compact: function() {

    return this.select(function(value) {

      return value != null;

    });

  },



  flatten: function() {

    return this.inject([], function(array, value) {

      return array.concat(Object.isArray(value) ?

        value.flatten() : [value]);

    });

  },



  without: function() {

    var values = $A(arguments);

    return this.select(function(value) {

      return !values.include(value);

    });

  },



  reverse: function(inline) {

    return (inline !== false ? this : this.toArray())._reverse();

  },



  reduce: function() {

    return this.length > 1 ? this : this[0];

  },



  uniq: function(sorted) {

    return this.inject([], function(array, value, index) {

      if (0 == index || (sorted ? array.last() != value : !array.include(value)))

        array.push(value);

      return array;

    });

  },



  intersect: function(array) {

    return this.uniq().findAll(function(item) {

      return array.detect(function(value) { return item === value });

    });

  },



  clone: function() {

    return [].concat(this);

  },



  size: function() {

    return this.length;

  },



  inspect: function() {

    return '[' + this.map(Object.inspect).join(', ') + ']';

  },



  toJSON: function() {

    var results = [];

    this.each(function(object) {

      var value = Object.toJSON(object);

      if (!Object.isUndefined(value)) results.push(value);

    });

    return '[' + results.join(', ') + ']';

  }

});



// use native browser JS 1.6 implementation if available

if (Object.isFunction(Array.prototype.forEach))

  Array.prototype._each = Array.prototype.forEach;



if (!Array.prototype.indexOf) Array.prototype.indexOf = function(item, i) {

  i || (i = 0);

  var length = this.length;

  if (i < 0) i = length + i;

  for (; i < length; i++)

    if (this[i] === item) return i;

  return -1;

};



if (!Array.prototype.lastIndexOf) Array.prototype.lastIndexOf = function(item, i) {

  i = isNaN(i) ? this.length : (i < 0 ? this.length + i : i) + 1;

  var n = this.slice(0, i).reverse().indexOf(item);

  return (n < 0) ? n : i - n - 1;

};



Array.prototype.toArray = Array.prototype.clone;



function $w(string) {

  if (!Object.isString(string)) return [];

  string = string.strip();

  return string ? string.split(/\s+/) : [];

}



if (Prototype.Browser.Opera){

  Array.prototype.concat = function() {

    var array = [];

    for (var i = 0, length = this.length; i < length; i++) array.push(this[i]);

    for (var i = 0, length = arguments.length; i < length; i++) {

      if (Object.isArray(arguments[i])) {

        for (var j = 0, arrayLength = arguments[i].length; j < arrayLength; j++)

          array.push(arguments[i][j]);

      } else {

        array.push(arguments[i]);

      }

    }

    return array;

  };

}

Object.extend(Number.prototype, {

  toColorPart: function() {

    return this.toPaddedString(2, 16);

  },



  succ: function() {

    return this + 1;

  },



  times: function(iterator) {

    $R(0, this, true).each(iterator);

    return this;

  },



  toPaddedString: function(length, radix) {

    var string = this.toString(radix || 10);

    return '0'.times(length - string.length) + string;

  },



  toJSON: function() {

    return isFinite(this) ? this.toString() : 'null';

  }

});



$w('abs round ceil floor').each(function(method){

  Number.prototype[method] = Math[method].methodize();

});

function $H(object) {

  return new Hash(object);

};



var Hash = Class.create(Enumerable, (function() {



  function toQueryPair(key, value) {

    if (Object.isUndefined(value)) return key;

    return key + '=' + encodeURIComponent(String.interpret(value));

  }



  return {

    initialize: function(object) {

      this._object = Object.isHash(object) ? object.toObject() : Object.clone(object);

    },



    _each: function(iterator) {

      for (var key in this._object) {

        var value = this._object[key], pair = [key, value];

        pair.key = key;

        pair.value = value;

        iterator(pair);

      }

    },



    set: function(key, value) {

      return this._object[key] = value;

    },



    get: function(key) {

      return this._object[key];

    },



    unset: function(key) {

      var value = this._object[key];

      delete this._object[key];

      return value;

    },



    toObject: function() {

      return Object.clone(this._object);

    },



    keys: function() {

      return this.pluck('key');

    },



    values: function() {

      return this.pluck('value');

    },



    index: function(value) {

      var match = this.detect(function(pair) {

        return pair.value === value;

      });

      return match && match.key;

    },



    merge: function(object) {

      return this.clone().update(object);

    },



    update: function(object) {

      return new Hash(object).inject(this, function(result, pair) {

        result.set(pair.key, pair.value);

        return result;

      });

    },



    toQueryString: function() {

      return this.map(function(pair) {

        var key = encodeURIComponent(pair.key), values = pair.value;



        if (values && typeof values == 'object') {

          if (Object.isArray(values))

            return values.map(toQueryPair.curry(key)).join('&');

        }

        return toQueryPair(key, values);

      }).join('&');

    },



    inspect: function() {

      return '#<Hash:{' + this.map(function(pair) {

        return pair.map(Object.inspect).join(': ');

      }).join(', ') + '}>';

    },



    toJSON: function() {

      return Object.toJSON(this.toObject());

    },



    clone: function() {

      return new Hash(this);

    }

  }

})());



Hash.prototype.toTemplateReplacements = Hash.prototype.toObject;

Hash.from = $H;

var ObjectRange = Class.create(Enumerable, {

  initialize: function(start, end, exclusive) {

    this.start = start;

    this.end = end;

    this.exclusive = exclusive;

  },



  _each: function(iterator) {

    var value = this.start;

    while (this.include(value)) {

      iterator(value);

      value = value.succ();

    }

  },



  include: function(value) {

    if (value < this.start)

      return false;

    if (this.exclusive)

      return value < this.end;

    return value <= this.end;

  }

});



var $R = function(start, end, exclusive) {

  return new ObjectRange(start, end, exclusive);

};



var Ajax = {

  getTransport: function() {

    return Try.these(

      function() {return new XMLHttpRequest()},

      function() {return new ActiveXObject('Msxml2.XMLHTTP')},

      function() {return new ActiveXObject('Microsoft.XMLHTTP')}

    ) || false;

  },



  activeRequestCount: 0

};



Ajax.Responders = {

  responders: [],



  _each: function(iterator) {

    this.responders._each(iterator);

  },



  register: function(responder) {

    if (!this.include(responder))

      this.responders.push(responder);

  },



  unregister: function(responder) {

    this.responders = this.responders.without(responder);

  },



  dispatch: function(callback, request, transport, json) {

    this.each(function(responder) {

      if (Object.isFunction(responder[callback])) {

        try {

          responder[callback].apply(responder, [request, transport, json]);

        } catch (e) { }

      }

    });

  }

};



Object.extend(Ajax.Responders, Enumerable);



Ajax.Responders.register({

  onCreate:   function() { Ajax.activeRequestCount++ },

  onComplete: function() { Ajax.activeRequestCount-- }

});



Ajax.Base = Class.create({

  initialize: function(options) {

    this.options = {

      method:       'post',

      asynchronous: true,

      contentType:  'application/x-www-form-urlencoded',

      encoding:     'UTF-8',

      parameters:   '',

      evalJSON:     true,

      evalJS:       true

    };

    Object.extend(this.options, options || { });



    this.options.method = this.options.method.toLowerCase();



    if (Object.isString(this.options.parameters))

      this.options.parameters = this.options.parameters.toQueryParams();

    else if (Object.isHash(this.options.parameters))

      this.options.parameters = this.options.parameters.toObject();

  }

});



Ajax.Request = Class.create(Ajax.Base, {

  _complete: false,



  initialize: function($super, url, options) {

    $super(options);

    this.transport = Ajax.getTransport();

    this.request(url);

  },



  request: function(url) {

    this.url = url;

    this.method = this.options.method;

    var params = Object.clone(this.options.parameters);



    if (!['get', 'post'].include(this.method)) {

      // simulate other verbs over post

      params['_method'] = this.method;

      this.method = 'post';

    }



    this.parameters = params;



    if (params = Object.toQueryString(params)) {

      // when GET, append parameters to URL

      if (this.method == 'get')

        this.url += (this.url.include('?') ? '&' : '?') + params;

      else if (/Konqueror|Safari|KHTML/.test(navigator.userAgent))

        params += '&_=';

    }



    try {

      var response = new Ajax.Response(this);

      if (this.options.onCreate) this.options.onCreate(response);

      Ajax.Responders.dispatch('onCreate', this, response);



      this.transport.open(this.method.toUpperCase(), this.url,

        this.options.asynchronous);



      if (this.options.asynchronous) this.respondToReadyState.bind(this).defer(1);



      this.transport.onreadystatechange = this.onStateChange.bind(this);

      this.setRequestHeaders();



      this.body = this.method == 'post' ? (this.options.postBody || params) : null;

      this.transport.send(this.body);



      /* Force Firefox to handle ready state 4 for synchronous requests */

      if (!this.options.asynchronous && this.transport.overrideMimeType)

        this.onStateChange();



    }

    catch (e) {

      this.dispatchException(e);

    }

  },



  onStateChange: function() {

    var readyState = this.transport.readyState;

    if (readyState > 1 && !((readyState == 4) && this._complete))

      this.respondToReadyState(this.transport.readyState);

  },



  setRequestHeaders: function() {

    var headers = {

      'X-Requested-With': 'XMLHttpRequest',

      'X-Prototype-Version': Prototype.Version,

      'Accept': 'text/javascript, text/html, application/xml, text/xml, */*'

    };



    if (this.method == 'post') {

      headers['Content-type'] = this.options.contentType +

        (this.options.encoding ? '; charset=' + this.options.encoding : '');



      /* Force "Connection: close" for older Mozilla browsers to work

       * around a bug where XMLHttpRequest sends an incorrect

       * Content-length header. See Mozilla Bugzilla #246651.

       */

      if (this.transport.overrideMimeType &&

          (navigator.userAgent.match(/Gecko\/(\d{4})/) || [0,2005])[1] < 2005)

            headers['Connection'] = 'close';

    }



    // user-defined headers

    if (typeof this.options.requestHeaders == 'object') {

      var extras = this.options.requestHeaders;



      if (Object.isFunction(extras.push))

        for (var i = 0, length = extras.length; i < length; i += 2)

          headers[extras[i]] = extras[i+1];

      else

        $H(extras).each(function(pair) { headers[pair.key] = pair.value });

    }



    for (var name in headers)

      this.transport.setRequestHeader(name, headers[name]);

  },



  success: function() {

    var status = this.getStatus();

    return !status || (status >= 200 && status < 300);

  },



  getStatus: function() {

    try {

      return this.transport.status || 0;

    } catch (e) { return 0 }

  },



  respondToReadyState: function(readyState) {

    var state = Ajax.Request.Events[readyState], response = new Ajax.Response(this);



    if (state == 'Complete') {

      try {

        this._complete = true;

        (this.options['on' + response.status]

         || this.options['on' + (this.success() ? 'Success' : 'Failure')]

         || Prototype.emptyFunction)(response, response.headerJSON);

      } catch (e) {

        this.dispatchException(e);

      }



      var contentType = response.getHeader('Content-type');

      if (this.options.evalJS == 'force'

          || (this.options.evalJS && this.isSameOrigin() && contentType

          && contentType.match(/^\s*(text|application)\/(x-)?(java|ecma)script(;.*)?\s*$/i)))

        this.evalResponse();

    }



    try {

      (this.options['on' + state] || Prototype.emptyFunction)(response, response.headerJSON);

      Ajax.Responders.dispatch('on' + state, this, response, response.headerJSON);

    } catch (e) {

      this.dispatchException(e);

    }



    if (state == 'Complete') {

      // avoid memory leak in MSIE: clean up

      this.transport.onreadystatechange = Prototype.emptyFunction;

    }

  },



  isSameOrigin: function() {

    var m = this.url.match(/^\s*https?:\/\/[^\/]*/);

    return !m || (m[0] == '#{protocol}//#{domain}#{port}'.interpolate({

      protocol: location.protocol,

      domain: document.domain,

      port: location.port ? ':' + location.port : ''

    }));

  },



  getHeader: function(name) {

    try {

      return this.transport.getResponseHeader(name) || null;

    } catch (e) { return null }

  },



  evalResponse: function() {

    try {

      return eval((this.transport.responseText || '').unfilterJSON());

    } catch (e) {

      this.dispatchException(e);

    }

  },



  dispatchException: function(exception) {

    (this.options.onException || Prototype.emptyFunction)(this, exception);

    Ajax.Responders.dispatch('onException', this, exception);

  }

});



Ajax.Request.Events =

  ['Uninitialized', 'Loading', 'Loaded', 'Interactive', 'Complete'];



Ajax.Response = Class.create({

  initialize: function(request){

    this.request = request;

    var transport  = this.transport  = request.transport,

        readyState = this.readyState = transport.readyState;



    if((readyState > 2 && !Prototype.Browser.IE) || readyState == 4) {

      this.status       = this.getStatus();

      this.statusText   = this.getStatusText();

      this.responseText = String.interpret(transport.responseText);

      this.headerJSON   = this._getHeaderJSON();

    }



    if(readyState == 4) {

      var xml = transport.responseXML;

      this.responseXML  = Object.isUndefined(xml) ? null : xml;

      this.responseJSON = this._getResponseJSON();

    }

  },



  status:      0,

  statusText: '',



  getStatus: Ajax.Request.prototype.getStatus,



  getStatusText: function() {

    try {

      return this.transport.statusText || '';

    } catch (e) { return '' }

  },



  getHeader: Ajax.Request.prototype.getHeader,



  getAllHeaders: function() {

    try {

      return this.getAllResponseHeaders();

    } catch (e) { return null }

  },



  getResponseHeader: function(name) {

    return this.transport.getResponseHeader(name);

  },



  getAllResponseHeaders: function() {

    return this.transport.getAllResponseHeaders();

  },



  _getHeaderJSON: function() {

    var json = this.getHeader('X-JSON');

    if (!json) return null;

    json = decodeURIComponent(escape(json));

    try {

      return json.evalJSON(this.request.options.sanitizeJSON ||

        !this.request.isSameOrigin());

    } catch (e) {

      this.request.dispatchException(e);

    }

  },



  _getResponseJSON: function() {

    var options = this.request.options;

    if (!options.evalJSON || (options.evalJSON != 'force' &&

      !(this.getHeader('Content-type') || '').include('application/json')) ||

        this.responseText.blank())

          return null;

    try {

      return this.responseText.evalJSON(options.sanitizeJSON ||

        !this.request.isSameOrigin());

    } catch (e) {

      this.request.dispatchException(e);

    }

  }

});



Ajax.Updater = Class.create(Ajax.Request, {

  initialize: function($super, container, url, options) {

    this.container = {

      success: (container.success || container),

      failure: (container.failure || (container.success ? null : container))

    };



    options = Object.clone(options);

    var onComplete = options.onComplete;

    options.onComplete = (function(response, json) {

      this.updateContent(response.responseText);

      if (Object.isFunction(onComplete)) onComplete(response, json);

    }).bind(this);



    $super(url, options);

  },



  updateContent: function(responseText) {

    var receiver = this.container[this.success() ? 'success' : 'failure'],

        options = this.options;



    if (!options.evalScripts) responseText = responseText.stripScripts();



    if (receiver = $(receiver)) {

      if (options.insertion) {

        if (Object.isString(options.insertion)) {

          var insertion = { }; insertion[options.insertion] = responseText;

          receiver.insert(insertion);

        }

        else options.insertion(receiver, responseText);

      }

      else receiver.update(responseText);

    }

  }

});



Ajax.PeriodicalUpdater = Class.create(Ajax.Base, {

  initialize: function($super, container, url, options) {

    $super(options);

    this.onComplete = this.options.onComplete;



    this.frequency = (this.options.frequency || 2);

    this.decay = (this.options.decay || 1);



    this.updater = { };

    this.container = container;

    this.url = url;



    this.start();

  },



  start: function() {

    this.options.onComplete = this.updateComplete.bind(this);

    this.onTimerEvent();

  },



  stop: function() {

    this.updater.options.onComplete = undefined;

    clearTimeout(this.timer);

    (this.onComplete || Prototype.emptyFunction).apply(this, arguments);

  },



  updateComplete: function(response) {

    if (this.options.decay) {

      this.decay = (response.responseText == this.lastText ?

        this.decay * this.options.decay : 1);



      this.lastText = response.responseText;

    }

    this.timer = this.onTimerEvent.bind(this).delay(this.decay * this.frequency);

  },



  onTimerEvent: function() {

    this.updater = new Ajax.Updater(this.container, this.url, this.options);

  }

});

function $(element) {

  if (arguments.length > 1) {

    for (var i = 0, elements = [], length = arguments.length; i < length; i++)

      elements.push($(arguments[i]));

    return elements;

  }

  if (Object.isString(element))

    element = document.getElementById(element);

  return Element.extend(element);

}



if (Prototype.BrowserFeatures.XPath) {

  document._getElementsByXPath = function(expression, parentElement) {

    var results = [];

    var query = document.evaluate(expression, $(parentElement) || document,

      null, XPathResult.ORDERED_NODE_SNAPSHOT_TYPE, null);

    for (var i = 0, length = query.snapshotLength; i < length; i++)

      results.push(Element.extend(query.snapshotItem(i)));

    return results;

  };

}



/*--------------------------------------------------------------------------*/



if (!window.Node) var Node = { };



if (!Node.ELEMENT_NODE) {

  // DOM level 2 ECMAScript Language Binding

  Object.extend(Node, {

    ELEMENT_NODE: 1,

    ATTRIBUTE_NODE: 2,

    TEXT_NODE: 3,

    CDATA_SECTION_NODE: 4,

    ENTITY_REFERENCE_NODE: 5,

    ENTITY_NODE: 6,

    PROCESSING_INSTRUCTION_NODE: 7,

    COMMENT_NODE: 8,

    DOCUMENT_NODE: 9,

    DOCUMENT_TYPE_NODE: 10,

    DOCUMENT_FRAGMENT_NODE: 11,

    NOTATION_NODE: 12

  });

}



(function() {

  var element = this.Element;

  this.Element = function(tagName, attributes) {

    attributes = attributes || { };

    tagName = tagName.toLowerCase();

    var cache = Element.cache;

    if (Prototype.Browser.IE && attributes.name) {

      tagName = '<' + tagName + ' name="' + attributes.name + '">';

      delete attributes.name;

      return Element.writeAttribute(document.createElement(tagName), attributes);

    }

    if (!cache[tagName]) cache[tagName] = Element.extend(document.createElement(tagName));

    return Element.writeAttribute(cache[tagName].cloneNode(false), attributes);

  };

  Object.extend(this.Element, element || { });

}).call(window);



Element.cache = { };



Element.Methods = {

  visible: function(element) {

    return $(element).style.display != 'none';

  },



  toggle: function(element) {

    element = $(element);

    Element[Element.visible(element) ? 'hide' : 'show'](element);

    return element;

  },



  hide: function(element) {

    $(element).style.display = 'none';

    return element;

  },



  show: function(element) {

    $(element).style.display = '';

    return element;

  },



  remove: function(element) {

    element = $(element);

    element.parentNode.removeChild(element);

    return element;

  },



  update: function(element, content) {

    element = $(element);

    if (content && content.toElement) content = content.toElement();

    if (Object.isElement(content)) return element.update().insert(content);

    content = Object.toHTML(content);

    element.innerHTML = content.stripScripts();

    content.evalScripts.bind(content).defer();

    return element;

  },



  replace: function(element, content) {

    element = $(element);

    if (content && content.toElement) content = content.toElement();

    else if (!Object.isElement(content)) {

      content = Object.toHTML(content);

      var range = element.ownerDocument.createRange();

      range.selectNode(element);

      content.evalScripts.bind(content).defer();

      content = range.createContextualFragment(content.stripScripts());

    }

    element.parentNode.replaceChild(content, element);

    return element;

  },



  insert: function(element, insertions) {

    element = $(element);



    if (Object.isString(insertions) || Object.isNumber(insertions) ||

        Object.isElement(insertions) || (insertions && (insertions.toElement || insertions.toHTML)))

          insertions = {bottom:insertions};



    var content, insert, tagName, childNodes;



    for (var position in insertions) {

      content  = insertions[position];

      position = position.toLowerCase();

      insert = Element._insertionTranslations[position];



      if (content && content.toElement) content = content.toElement();

      if (Object.isElement(content)) {

        insert(element, content);

        continue;

      }



      content = Object.toHTML(content);



      tagName = ((position == 'before' || position == 'after')

        ? element.parentNode : element).tagName.toUpperCase();



      childNodes = Element._getContentFromAnonymousElement(tagName, content.stripScripts());



      if (position == 'top' || position == 'after') childNodes.reverse();

      childNodes.each(insert.curry(element));



      content.evalScripts.bind(content).defer();

    }



    return element;

  },



  wrap: function(element, wrapper, attributes) {

    element = $(element);

    if (Object.isElement(wrapper))

      $(wrapper).writeAttribute(attributes || { });

    else if (Object.isString(wrapper)) wrapper = new Element(wrapper, attributes);

    else wrapper = new Element('div', wrapper);

    if (element.parentNode)

      element.parentNode.replaceChild(wrapper, element);

    wrapper.appendChild(element);

    return wrapper;

  },



  inspect: function(element) {

    element = $(element);

    var result = '<' + element.tagName.toLowerCase();

    $H({'id': 'id', 'className': 'class'}).each(function(pair) {

      var property = pair.first(), attribute = pair.last();

      var value = (element[property] || '').toString();

      if (value) result += ' ' + attribute + '=' + value.inspect(true);

    });

    return result + '>';

  },



  recursivelyCollect: function(element, property) {

    element = $(element);

    var elements = [];

    while (element = element[property])

      if (element.nodeType == 1)

        elements.push(Element.extend(element));

    return elements;

  },



  ancestors: function(element) {

    return $(element).recursivelyCollect('parentNode');

  },



  descendants: function(element) {

    return $(element).select("*");

  },



  firstDescendant: function(element) {

    element = $(element).firstChild;

    while (element && element.nodeType != 1) element = element.nextSibling;

    return $(element);

  },



  immediateDescendants: function(element) {

    if (!(element = $(element).firstChild)) return [];

    while (element && element.nodeType != 1) element = element.nextSibling;

    if (element) return [element].concat($(element).nextSiblings());

    return [];

  },



  previousSiblings: function(element) {

    return $(element).recursivelyCollect('previousSibling');

  },



  nextSiblings: function(element) {

    return $(element).recursivelyCollect('nextSibling');

  },



  siblings: function(element) {

    element = $(element);

    return element.previousSiblings().reverse().concat(element.nextSiblings());

  },



  match: function(element, selector) {

    if (Object.isString(selector))

      selector = new Selector(selector);

    return selector.match($(element));

  },



  up: function(element, expression, index) {

    element = $(element);

    if (arguments.length == 1) return $(element.parentNode);

    var ancestors = element.ancestors();

    return Object.isNumber(expression) ? ancestors[expression] :

      Selector.findElement(ancestors, expression, index);

  },



  down: function(element, expression, index) {

    element = $(element);

    if (arguments.length == 1) return element.firstDescendant();

    return Object.isNumber(expression) ? element.descendants()[expression] :

      element.select(expression)[index || 0];

  },



  previous: function(element, expression, index) {

    element = $(element);

    if (arguments.length == 1) return $(Selector.handlers.previousElementSibling(element));

    var previousSiblings = element.previousSiblings();

    return Object.isNumber(expression) ? previousSiblings[expression] :

      Selector.findElement(previousSiblings, expression, index);

  },



  next: function(element, expression, index) {

    element = $(element);

    if (arguments.length == 1) return $(Selector.handlers.nextElementSibling(element));

    var nextSiblings = element.nextSiblings();

    return Object.isNumber(expression) ? nextSiblings[expression] :

      Selector.findElement(nextSiblings, expression, index);

  },



  select: function() {

    var args = $A(arguments), element = $(args.shift());

    return Selector.findChildElements(element, args);

  },



  adjacent: function() {

    var args = $A(arguments), element = $(args.shift());

    return Selector.findChildElements(element.parentNode, args).without(element);

  },



  identify: function(element) {

    element = $(element);

    var id = element.readAttribute('id'), self = arguments.callee;

    if (id) return id;

    do { id = 'anonymous_element_' + self.counter++ } while ($(id));

    element.writeAttribute('id', id);

    return id;

  },



  readAttribute: function(element, name) {

    element = $(element);

    if (Prototype.Browser.IE) {

      var t = Element._attributeTranslations.read;

      if (t.values[name]) return t.values[name](element, name);

      if (t.names[name]) name = t.names[name];

      if (name.include(':')) {

        return (!element.attributes || !element.attributes[name]) ? null :

         element.attributes[name].value;

      }

    }

    return element.getAttribute(name);

  },



  writeAttribute: function(element, name, value) {

    element = $(element);

    var attributes = { }, t = Element._attributeTranslations.write;



    if (typeof name == 'object') attributes = name;

    else attributes[name] = Object.isUndefined(value) ? true : value;



    for (var attr in attributes) {

      name = t.names[attr] || attr;

      value = attributes[attr];

      if (t.values[attr]) name = t.values[attr](element, value);

      if (value === false || value === null)

        element.removeAttribute(name);

      else if (value === true)

        element.setAttribute(name, name);

      else element.setAttribute(name, value);

    }

    return element;

  },



  getHeight: function(element) {

    return $(element).getDimensions().height;

  },



  getWidth: function(element) {

    return $(element).getDimensions().width;

  },



  classNames: function(element) {

    return new Element.ClassNames(element);

  },



  hasClassName: function(element, className) {

    if (!(element = $(element))) return;

    var elementClassName = element.className;

    return (elementClassName.length > 0 && (elementClassName == className ||

      new RegExp("(^|\\s)" + className + "(\\s|$)").test(elementClassName)));

  },



  addClassName: function(element, className) {

    if (!(element = $(element))) return;

    if (!element.hasClassName(className))

      element.className += (element.className ? ' ' : '') + className;

    return element;

  },



  removeClassName: function(element, className) {

    if (!(element = $(element))) return;

    element.className = element.className.replace(

      new RegExp("(^|\\s+)" + className + "(\\s+|$)"), ' ').strip();

    return element;

  },



  toggleClassName: function(element, className) {

    if (!(element = $(element))) return;

    return element[element.hasClassName(className) ?

      'removeClassName' : 'addClassName'](className);

  },



  // removes whitespace-only text node children

  cleanWhitespace: function(element) {

    element = $(element);

    var node = element.firstChild;

    while (node) {

      var nextNode = node.nextSibling;

      if (node.nodeType == 3 && !/\S/.test(node.nodeValue))

        element.removeChild(node);

      node = nextNode;

    }

    return element;

  },



  empty: function(element) {

    return $(element).innerHTML.blank();

  },



  descendantOf: function(element, ancestor) {

    element = $(element), ancestor = $(ancestor);

    var originalAncestor = ancestor;



    if (element.compareDocumentPosition)

      return (element.compareDocumentPosition(ancestor) & 8) === 8;



    if (element.sourceIndex && !Prototype.Browser.Opera) {

      var e = element.sourceIndex, a = ancestor.sourceIndex,

       nextAncestor = ancestor.nextSibling;

      if (!nextAncestor) {

        do { ancestor = ancestor.parentNode; }

        while (!(nextAncestor = ancestor.nextSibling) && ancestor.parentNode);

      }

      if (nextAncestor && nextAncestor.sourceIndex)

       return (e > a && e < nextAncestor.sourceIndex);

    }



    while (element = element.parentNode)

      if (element == originalAncestor) return true;

    return false;

  },



  scrollTo: function(element) {

    element = $(element);

    var pos = element.cumulativeOffset();

    window.scrollTo(pos[0], pos[1]);

    return element;

  },



  getStyle: function(element, style) {

    element = $(element);

    style = style == 'float' ? 'cssFloat' : style.camelize();

    var value = element.style[style];

    if (!value) {

      var css = document.defaultView.getComputedStyle(element, null);

      value = css ? css[style] : null;

    }

    if (style == 'opacity') return value ? parseFloat(value) : 1.0;

    return value == 'auto' ? null : value;

  },



  getOpacity: function(element) {

    return $(element).getStyle('opacity');

  },



  setStyle: function(element, styles) {

    element = $(element);

    var elementStyle = element.style, match;

    if (Object.isString(styles)) {

      element.style.cssText += ';' + styles;

      return styles.include('opacity') ?

        element.setOpacity(styles.match(/opacity:\s*(\d?\.?\d*)/)[1]) : element;

    }

    for (var property in styles)

      if (property == 'opacity') element.setOpacity(styles[property]);

      else

        elementStyle[(property == 'float' || property == 'cssFloat') ?

          (Object.isUndefined(elementStyle.styleFloat) ? 'cssFloat' : 'styleFloat') :

            property] = styles[property];



    return element;

  },



  setOpacity: function(element, value) {

    element = $(element);

    element.style.opacity = (value == 1 || value === '') ? '' :

      (value < 0.00001) ? 0 : value;

    return element;

  },



  getDimensions: function(element) {

    element = $(element);

    var display = $(element).getStyle('display');

    if (display != 'none' && display != null) // Safari bug

      return {width: element.offsetWidth, height: element.offsetHeight};



    // All *Width and *Height properties give 0 on elements with display none,

    // so enable the element temporarily

    var els = element.style;

    var originalVisibility = els.visibility;

    var originalPosition = els.position;

    var originalDisplay = els.display;

    els.visibility = 'hidden';

    els.position = 'absolute';

    els.display = 'block';

    var originalWidth = element.clientWidth;

    var originalHeight = element.clientHeight;

    els.display = originalDisplay;

    els.position = originalPosition;

    els.visibility = originalVisibility;

    return {width: originalWidth, height: originalHeight};

  },



  makePositioned: function(element) {

    element = $(element);

    var pos = Element.getStyle(element, 'position');

    if (pos == 'static' || !pos) {

      element._madePositioned = true;

      element.style.position = 'relative';

      // Opera returns the offset relative to the positioning context, when an

      // element is position relative but top and left have not been defined

      if (window.opera) {

        element.style.top = 0;

        element.style.left = 0;

      }

    }

    return element;

  },



  undoPositioned: function(element) {

    element = $(element);

    if (element._madePositioned) {

      element._madePositioned = undefined;

      element.style.position =

        element.style.top =

        element.style.left =

        element.style.bottom =

        element.style.right = '';

    }

    return element;

  },



  makeClipping: function(element) {

    element = $(element);

    if (element._overflow) return element;

    element._overflow = Element.getStyle(element, 'overflow') || 'auto';

    if (element._overflow !== 'hidden')

      element.style.overflow = 'hidden';

    return element;

  },



  undoClipping: function(element) {

    element = $(element);

    if (!element._overflow) return element;

    element.style.overflow = element._overflow == 'auto' ? '' : element._overflow;

    element._overflow = null;

    return element;

  },



  cumulativeOffset: function(element) {

    var valueT = 0, valueL = 0;

    do {

      valueT += element.offsetTop  || 0;

      valueL += element.offsetLeft || 0;

      element = element.offsetParent;

    } while (element);

    return Element._returnOffset(valueL, valueT);

  },



  positionedOffset: function(element) {

    var valueT = 0, valueL = 0;

    do {

      valueT += element.offsetTop  || 0;

      valueL += element.offsetLeft || 0;

      element = element.offsetParent;

      if (element) {

        if (element.tagName == 'BODY') break;

        var p = Element.getStyle(element, 'position');

        if (p !== 'static') break;

      }

    } while (element);

    return Element._returnOffset(valueL, valueT);

  },



  absolutize: function(element) {

    element = $(element);

    if (element.getStyle('position') == 'absolute') return;

    // Position.prepare(); // To be done manually by Scripty when it needs it.



    var offsets = element.positionedOffset();

    var top     = offsets[1];

    var left    = offsets[0];

    var width   = element.clientWidth;

    var height  = element.clientHeight;



    element._originalLeft   = left - parseFloat(element.style.left  || 0);

    element._originalTop    = top  - parseFloat(element.style.top || 0);

    element._originalWidth  = element.style.width;

    element._originalHeight = element.style.height;



    element.style.position = 'absolute';

    element.style.top    = top + 'px';

    element.style.left   = left + 'px';

    element.style.width  = width + 'px';

    element.style.height = height + 'px';

    return element;

  },



  relativize: function(element) {

    element = $(element);

    if (element.getStyle('position') == 'relative') return;

    // Position.prepare(); // To be done manually by Scripty when it needs it.



    element.style.position = 'relative';

    var top  = parseFloat(element.style.top  || 0) - (element._originalTop || 0);

    var left = parseFloat(element.style.left || 0) - (element._originalLeft || 0);



    element.style.top    = top + 'px';

    element.style.left   = left + 'px';

    element.style.height = element._originalHeight;

    element.style.width  = element._originalWidth;

    return element;

  },



  cumulativeScrollOffset: function(element) {

    var valueT = 0, valueL = 0;

    do {

      valueT += element.scrollTop  || 0;

      valueL += element.scrollLeft || 0;

      element = element.parentNode;

    } while (element);

    return Element._returnOffset(valueL, valueT);

  },



  getOffsetParent: function(element) {

    if (element.offsetParent) return $(element.offsetParent);

    if (element == document.body) return $(element);



    while ((element = element.parentNode) && element != document.body)

      if (Element.getStyle(element, 'position') != 'static')

        return $(element);



    return $(document.body);

  },



  viewportOffset: function(forElement) {

    var valueT = 0, valueL = 0;



    var element = forElement;

    do {

      valueT += element.offsetTop  || 0;

      valueL += element.offsetLeft || 0;



      // Safari fix

      if (element.offsetParent == document.body &&

        Element.getStyle(element, 'position') == 'absolute') break;



    } while (element = element.offsetParent);



    element = forElement;

    do {

      if (!Prototype.Browser.Opera || element.tagName == 'BODY') {

        valueT -= element.scrollTop  || 0;

        valueL -= element.scrollLeft || 0;

      }

    } while (element = element.parentNode);



    return Element._returnOffset(valueL, valueT);

  },



  clonePosition: function(element, source) {

    var options = Object.extend({

      setLeft:    true,

      setTop:     true,

      setWidth:   true,

      setHeight:  true,

      offsetTop:  0,

      offsetLeft: 0

    }, arguments[2] || { });



    // find page position of source

    source = $(source);

    var p = source.viewportOffset();



    // find coordinate system to use

    element = $(element);

    var delta = [0, 0];

    var parent = null;

    // delta [0,0] will do fine with position: fixed elements,

    // position:absolute needs offsetParent deltas

    if (Element.getStyle(element, 'position') == 'absolute') {

      parent = element.getOffsetParent();

      delta = parent.viewportOffset();

    }



    // correct by body offsets (fixes Safari)

    if (parent == document.body) {

      delta[0] -= document.body.offsetLeft;

      delta[1] -= document.body.offsetTop;

    }



    // set position

    if (options.setLeft)   element.style.left  = (p[0] - delta[0] + options.offsetLeft) + 'px';

    if (options.setTop)    element.style.top   = (p[1] - delta[1] + options.offsetTop) + 'px';

    if (options.setWidth)  element.style.width = source.offsetWidth + 'px';

    if (options.setHeight) element.style.height = source.offsetHeight + 'px';

    return element;

  }

};



Element.Methods.identify.counter = 1;



Object.extend(Element.Methods, {

  getElementsBySelector: Element.Methods.select,

  childElements: Element.Methods.immediateDescendants

});



Element._attributeTranslations = {

  write: {

    names: {

      className: 'class',

      htmlFor:   'for'

    },

    values: { }

  }

};



if (Prototype.Browser.Opera) {

  Element.Methods.getStyle = Element.Methods.getStyle.wrap(

    function(proceed, element, style) {

      switch (style) {

        case 'left': case 'top': case 'right': case 'bottom':

          if (proceed(element, 'position') === 'static') return null;

        case 'height': case 'width':

          // returns '0px' for hidden elements; we want it to return null

          if (!Element.visible(element)) return null;



          // returns the border-box dimensions rather than the content-box

          // dimensions, so we subtract padding and borders from the value

          var dim = parseInt(proceed(element, style), 10);



          if (dim !== element['offset' + style.capitalize()])

            return dim + 'px';



          var properties;

          if (style === 'height') {

            properties = ['border-top-width', 'padding-top',

             'padding-bottom', 'border-bottom-width'];

          }

          else {

            properties = ['border-left-width', 'padding-left',

             'padding-right', 'border-right-width'];

          }

          return properties.inject(dim, function(memo, property) {

            var val = proceed(element, property);

            return val === null ? memo : memo - parseInt(val, 10);

          }) + 'px';

        default: return proceed(element, style);

      }

    }

  );



  Element.Methods.readAttribute = Element.Methods.readAttribute.wrap(

    function(proceed, element, attribute) {

      if (attribute === 'title') return element.title;

      return proceed(element, attribute);

    }

  );

}



else if (Prototype.Browser.IE) {

  // IE doesn't report offsets correctly for static elements, so we change them

  // to "relative" to get the values, then change them back.

  Element.Methods.getOffsetParent = Element.Methods.getOffsetParent.wrap(

    function(proceed, element) {

      element = $(element);

      var position = element.getStyle('position');

      if (position !== 'static') return proceed(element);

      element.setStyle({ position: 'relative' });

      var value = proceed(element);

      element.setStyle({ position: position });

      return value;

    }

  );



  $w('positionedOffset viewportOffset').each(function(method) {

    Element.Methods[method] = Element.Methods[method].wrap(

      function(proceed, element) {

        element = $(element);

        var position = element.getStyle('position');

        if (position !== 'static') return proceed(element);

        // Trigger hasLayout on the offset parent so that IE6 reports

        // accurate offsetTop and offsetLeft values for position: fixed.

        var offsetParent = element.getOffsetParent();

        if (offsetParent && offsetParent.getStyle('position') === 'fixed')

          offsetParent.setStyle({ zoom: 1 });

        element.setStyle({ position: 'relative' });

        var value = proceed(element);

        element.setStyle({ position: position });

        return value;

      }

    );

  });



  Element.Methods.getStyle = function(element, style) {

    element = $(element);

    style = (style == 'float' || style == 'cssFloat') ? 'styleFloat' : style.camelize();

    var value = element.style[style];

    if (!value && element.currentStyle) value = element.currentStyle[style];



    if (style == 'opacity') {

      if (value = (element.getStyle('filter') || '').match(/alpha\(opacity=(.*)\)/))

        if (value[1]) return parseFloat(value[1]) / 100;

      return 1.0;

    }



    if (value == 'auto') {

      if ((style == 'width' || style == 'height') && (element.getStyle('display') != 'none'))

        return element['offset' + style.capitalize()] + 'px';

      return null;

    }

    return value;

  };



  Element.Methods.setOpacity = function(element, value) {

    function stripAlpha(filter){

      return filter.replace(/alpha\([^\)]*\)/gi,'');

    }

    element = $(element);

    var currentStyle = element.currentStyle;

    if ((currentStyle && !currentStyle.hasLayout) ||

      (!currentStyle && element.style.zoom == 'normal'))

        element.style.zoom = 1;



    var filter = element.getStyle('filter'), style = element.style;

    if (value == 1 || value === '') {

      (filter = stripAlpha(filter)) ?

        style.filter = filter : style.removeAttribute('filter');

      return element;

    } else if (value < 0.00001) value = 0;

    style.filter = stripAlpha(filter) +

      'alpha(opacity=' + (value * 100) + ')';

    return element;

  };



  Element._attributeTranslations = {

    read: {

      names: {

        'class': 'className',

        'for':   'htmlFor'

      },

      values: {

        _getAttr: function(element, attribute) {

          return element.getAttribute(attribute, 2);

        },

        _getAttrNode: function(element, attribute) {

          var node = element.getAttributeNode(attribute);

          return node ? node.value : "";

        },

        _getEv: function(element, attribute) {

          attribute = element.getAttribute(attribute);

          return attribute ? attribute.toString().slice(23, -2) : null;

        },

        _flag: function(element, attribute) {

          return $(element).hasAttribute(attribute) ? attribute : null;

        },

        style: function(element) {

          return element.style.cssText.toLowerCase();

        },

        title: function(element) {

          return element.title;

        }

      }

    }

  };



  Element._attributeTranslations.write = {

    names: Object.extend({

      cellpadding: 'cellPadding',

      cellspacing: 'cellSpacing'

    }, Element._attributeTranslations.read.names),

    values: {

      checked: function(element, value) {

        element.checked = !!value;

      },



      style: function(element, value) {

        element.style.cssText = value ? value : '';

      }

    }

  };



  Element._attributeTranslations.has = {};



  $w('colSpan rowSpan vAlign dateTime accessKey tabIndex ' +

      'encType maxLength readOnly longDesc').each(function(attr) {

    Element._attributeTranslations.write.names[attr.toLowerCase()] = attr;

    Element._attributeTranslations.has[attr.toLowerCase()] = attr;

  });



  (function(v) {

    Object.extend(v, {

      href:        v._getAttr,

      src:         v._getAttr,

      type:        v._getAttr,

      action:      v._getAttrNode,

      disabled:    v._flag,

      checked:     v._flag,

      readonly:    v._flag,

      multiple:    v._flag,

      onload:      v._getEv,

      onunload:    v._getEv,

      onclick:     v._getEv,

      ondblclick:  v._getEv,

      onmousedown: v._getEv,

      onmouseup:   v._getEv,

      onmouseover: v._getEv,

      onmousemove: v._getEv,

      onmouseout:  v._getEv,

      onfocus:     v._getEv,

      onblur:      v._getEv,

      onkeypress:  v._getEv,

      onkeydown:   v._getEv,

      onkeyup:     v._getEv,

      onsubmit:    v._getEv,

      onreset:     v._getEv,

      onselect:    v._getEv,

      onchange:    v._getEv

    });

  })(Element._attributeTranslations.read.values);

}



else if (Prototype.Browser.Gecko && /rv:1\.8\.0/.test(navigator.userAgent)) {

  Element.Methods.setOpacity = function(element, value) {

    element = $(element);

    element.style.opacity = (value == 1) ? 0.999999 :

      (value === '') ? '' : (value < 0.00001) ? 0 : value;

    return element;

  };

}



else if (Prototype.Browser.WebKit) {

  Element.Methods.setOpacity = function(element, value) {

    element = $(element);

    element.style.opacity = (value == 1 || value === '') ? '' :

      (value < 0.00001) ? 0 : value;



    if (value == 1)

      if(element.tagName == 'IMG' && element.width) {

        element.width++; element.width--;

      } else try {

        var n = document.createTextNode(' ');

        element.appendChild(n);

        element.removeChild(n);

      } catch (e) { }



    return element;

  };



  // Safari returns margins on body which is incorrect if the child is absolutely

  // positioned.  For performance reasons, redefine Element#cumulativeOffset for

  // KHTML/WebKit only.

  Element.Methods.cumulativeOffset = function(element) {

    var valueT = 0, valueL = 0;

    do {

      valueT += element.offsetTop  || 0;

      valueL += element.offsetLeft || 0;

      if (element.offsetParent == document.body)

        if (Element.getStyle(element, 'position') == 'absolute') break;



      element = element.offsetParent;

    } while (element);



    return Element._returnOffset(valueL, valueT);

  };

}



if (Prototype.Browser.IE || Prototype.Browser.Opera) {

  // IE and Opera are missing .innerHTML support for TABLE-related and SELECT elements

  Element.Methods.update = function(element, content) {

    element = $(element);



    if (content && content.toElement) content = content.toElement();

    if (Object.isElement(content)) return element.update().insert(content);



    content = Object.toHTML(content);

    var tagName = element.tagName.toUpperCase();



    if (tagName in Element._insertionTranslations.tags) {

      $A(element.childNodes).each(function(node) { element.removeChild(node) });

      Element._getContentFromAnonymousElement(tagName, content.stripScripts())

        .each(function(node) { element.appendChild(node) });

    }

    else element.innerHTML = content.stripScripts();



    content.evalScripts.bind(content).defer();

    return element;

  };

}



if ('outerHTML' in document.createElement('div')) {

  Element.Methods.replace = function(element, content) {

    element = $(element);



    if (content && content.toElement) content = content.toElement();

    if (Object.isElement(content)) {

      element.parentNode.replaceChild(content, element);

      return element;

    }



    content = Object.toHTML(content);

    var parent = element.parentNode, tagName = parent.tagName.toUpperCase();



    if (Element._insertionTranslations.tags[tagName]) {

      var nextSibling = element.next();

      var fragments = Element._getContentFromAnonymousElement(tagName, content.stripScripts());

      parent.removeChild(element);

      if (nextSibling)

        fragments.each(function(node) { parent.insertBefore(node, nextSibling) });

      else

        fragments.each(function(node) { parent.appendChild(node) });

    }

    else element.outerHTML = content.stripScripts();



    content.evalScripts.bind(content).defer();

    return element;

  };

}



Element._returnOffset = function(l, t) {

  var result = [l, t];

  result.left = l;

  result.top = t;

  return result;

};



Element._getContentFromAnonymousElement = function(tagName, html) {

  var div = new Element('div'), t = Element._insertionTranslations.tags[tagName];

  if (t) {

    div.innerHTML = t[0] + html + t[1];

    t[2].times(function() { div = div.firstChild });

  } else div.innerHTML = html;

  return $A(div.childNodes);

};



Element._insertionTranslations = {

  before: function(element, node) {

    element.parentNode.insertBefore(node, element);

  },

  top: function(element, node) {

    element.insertBefore(node, element.firstChild);

  },

  bottom: function(element, node) {

    element.appendChild(node);

  },

  after: function(element, node) {

    element.parentNode.insertBefore(node, element.nextSibling);

  },

  tags: {

    TABLE:  ['<table>',                '</table>',                   1],

    TBODY:  ['<table><tbody>',         '</tbody></table>',           2],

    TR:     ['<table><tbody><tr>',     '</tr></tbody></table>',      3],

    TD:     ['<table><tbody><tr><td>', '</td></tr></tbody></table>', 4],

    SELECT: ['<select>',               '</select>',                  1]

  }

};



(function() {

  Object.extend(this.tags, {

    THEAD: this.tags.TBODY,

    TFOOT: this.tags.TBODY,

    TH:    this.tags.TD

  });

}).call(Element._insertionTranslations);



Element.Methods.Simulated = {

  hasAttribute: function(element, attribute) {

    attribute = Element._attributeTranslations.has[attribute] || attribute;

    var node = $(element).getAttributeNode(attribute);

    return node && node.specified;

  }

};



Element.Methods.ByTag = { };



Object.extend(Element, Element.Methods);



if (!Prototype.BrowserFeatures.ElementExtensions &&

    document.createElement('div').__proto__) {

  window.HTMLElement = { };

  window.HTMLElement.prototype = document.createElement('div').__proto__;

  Prototype.BrowserFeatures.ElementExtensions = true;

}



Element.extend = (function() {

  if (Prototype.BrowserFeatures.SpecificElementExtensions)

    return Prototype.K;



  var Methods = { }, ByTag = Element.Methods.ByTag;



  var extend = Object.extend(function(element) {

    if (!element || element._extendedByPrototype ||

        element.nodeType != 1 || element == window) return element;



    var methods = Object.clone(Methods),

      tagName = element.tagName, property, value;



    // extend methods for specific tags

    if (ByTag[tagName]) Object.extend(methods, ByTag[tagName]);



    for (property in methods) {

      value = methods[property];

      if (Object.isFunction(value) && !(property in element))

        element[property] = value.methodize();

    }



    element._extendedByPrototype = Prototype.emptyFunction;

    return element;



  }, {

    refresh: function() {

      // extend methods for all tags (Safari doesn't need this)

      if (!Prototype.BrowserFeatures.ElementExtensions) {

        Object.extend(Methods, Element.Methods);

        Object.extend(Methods, Element.Methods.Simulated);

      }

    }

  });



  extend.refresh();

  return extend;

})();



Element.hasAttribute = function(element, attribute) {

  if (element.hasAttribute) return element.hasAttribute(attribute);

  return Element.Methods.Simulated.hasAttribute(element, attribute);

};



Element.addMethods = function(methods) {

  var F = Prototype.BrowserFeatures, T = Element.Methods.ByTag;



  if (!methods) {

    Object.extend(Form, Form.Methods);

    Object.extend(Form.Element, Form.Element.Methods);

    Object.extend(Element.Methods.ByTag, {

      "FORM":     Object.clone(Form.Methods),

      "INPUT":    Object.clone(Form.Element.Methods),

      "SELECT":   Object.clone(Form.Element.Methods),

      "TEXTAREA": Object.clone(Form.Element.Methods)

    });

  }



  if (arguments.length == 2) {

    var tagName = methods;

    methods = arguments[1];

  }



  if (!tagName) Object.extend(Element.Methods, methods || { });

  else {

    if (Object.isArray(tagName)) tagName.each(extend);

    else extend(tagName);

  }



  function extend(tagName) {

    tagName = tagName.toUpperCase();

    if (!Element.Methods.ByTag[tagName])

      Element.Methods.ByTag[tagName] = { };

    Object.extend(Element.Methods.ByTag[tagName], methods);

  }



  function copy(methods, destination, onlyIfAbsent) {

    onlyIfAbsent = onlyIfAbsent || false;

    for (var property in methods) {

      var value = methods[property];

      if (!Object.isFunction(value)) continue;

      if (!onlyIfAbsent || !(property in destination))

        destination[property] = value.methodize();

    }

  }



  function findDOMClass(tagName) {

    var klass;

    var trans = {

      "OPTGROUP": "OptGroup", "TEXTAREA": "TextArea", "P": "Paragraph",

      "FIELDSET": "FieldSet", "UL": "UList", "OL": "OList", "DL": "DList",

      "DIR": "Directory", "H1": "Heading", "H2": "Heading", "H3": "Heading",

      "H4": "Heading", "H5": "Heading", "H6": "Heading", "Q": "Quote",

      "INS": "Mod", "DEL": "Mod", "A": "Anchor", "IMG": "Image", "CAPTION":

      "TableCaption", "COL": "TableCol", "COLGROUP": "TableCol", "THEAD":

      "TableSection", "TFOOT": "TableSection", "TBODY": "TableSection", "TR":

      "TableRow", "TH": "TableCell", "TD": "TableCell", "FRAMESET":

      "FrameSet", "IFRAME": "IFrame"

    };

    if (trans[tagName]) klass = 'HTML' + trans[tagName] + 'Element';

    if (window[klass]) return window[klass];

    klass = 'HTML' + tagName + 'Element';

    if (window[klass]) return window[klass];

    klass = 'HTML' + tagName.capitalize() + 'Element';

    if (window[klass]) return window[klass];



    window[klass] = { };

    window[klass].prototype = document.createElement(tagName).__proto__;

    return window[klass];

  }



  if (F.ElementExtensions) {

    copy(Element.Methods, HTMLElement.prototype);

    copy(Element.Methods.Simulated, HTMLElement.prototype, true);

  }



  if (F.SpecificElementExtensions) {

    for (var tag in Element.Methods.ByTag) {

      var klass = findDOMClass(tag);

      if (Object.isUndefined(klass)) continue;

      copy(T[tag], klass.prototype);

    }

  }



  Object.extend(Element, Element.Methods);

  delete Element.ByTag;



  if (Element.extend.refresh) Element.extend.refresh();

  Element.cache = { };

};



document.viewport = {

  getDimensions: function() {

    var dimensions = { };

    var B = Prototype.Browser;

    $w('width height').each(function(d) {

      var D = d.capitalize();

      dimensions[d] = (B.WebKit && !document.evaluate) ? self['inner' + D] :

        (B.Opera) ? document.body['client' + D] : document.documentElement['client' + D];

    });

    return dimensions;

  },



  getWidth: function() {

    return this.getDimensions().width;

  },



  getHeight: function() {

    return this.getDimensions().height;

  },



  getScrollOffsets: function() {

    return Element._returnOffset(

      window.pageXOffset || document.documentElement.scrollLeft || document.body.scrollLeft,

      window.pageYOffset || document.documentElement.scrollTop || document.body.scrollTop);

  }

};

/* Portions of the Selector class are derived from Jack Slocumâ€™s DomQuery,

 * part of YUI-Ext version 0.40, distributed under the terms of an MIT-style

 * license.  Please see http://www.yui-ext.com/ for more information. */



var Selector = Class.create({

  initialize: function(expression) {

    this.expression = expression.strip();

    this.compileMatcher();

  },



  shouldUseXPath: function() {

    if (!Prototype.BrowserFeatures.XPath) return false;



    var e = this.expression;



    // Safari 3 chokes on :*-of-type and :empty

    if (Prototype.Browser.WebKit &&

     (e.include("-of-type") || e.include(":empty")))

      return false;



    // XPath can't do namespaced attributes, nor can it read

    // the "checked" property from DOM nodes

    if ((/(\[[\w-]*?:|:checked)/).test(this.expression))

      return false;



    return true;

  },



  compileMatcher: function() {

    if (this.shouldUseXPath())

      return this.compileXPathMatcher();



    var e = this.expression, ps = Selector.patterns, h = Selector.handlers,

        c = Selector.criteria, le, p, m;



    if (Selector._cache[e]) {

      this.matcher = Selector._cache[e];

      return;

    }



    this.matcher = ["this.matcher = function(root) {",

                    "var r = root, h = Selector.handlers, c = false, n;"];



    while (e && le != e && (/\S/).test(e)) {

      le = e;

      for (var i in ps) {

        p = ps[i];

        if (m = e.match(p)) {

          this.matcher.push(Object.isFunction(c[i]) ? c[i](m) :

    	      new Template(c[i]).evaluate(m));

          e = e.replace(m[0], '');

          break;

        }

      }

    }



    this.matcher.push("return h.unique(n);\n}");

    eval(this.matcher.join('\n'));

    Selector._cache[this.expression] = this.matcher;

  },



  compileXPathMatcher: function() {

    var e = this.expression, ps = Selector.patterns,

        x = Selector.xpath, le, m;



    if (Selector._cache[e]) {

      this.xpath = Selector._cache[e]; return;

    }



    this.matcher = ['.//*'];

    while (e && le != e && (/\S/).test(e)) {

      le = e;

      for (var i in ps) {

        if (m = e.match(ps[i])) {

          this.matcher.push(Object.isFunction(x[i]) ? x[i](m) :

            new Template(x[i]).evaluate(m));

          e = e.replace(m[0], '');

          break;

        }

      }

    }



    this.xpath = this.matcher.join('');

    Selector._cache[this.expression] = this.xpath;

  },



  findElements: function(root) {

    root = root || document;

    if (this.xpath) return document._getElementsByXPath(this.xpath, root);

    return this.matcher(root);

  },



  match: function(element) {

    this.tokens = [];



    var e = this.expression, ps = Selector.patterns, as = Selector.assertions;

    var le, p, m;



    while (e && le !== e && (/\S/).test(e)) {

      le = e;

      for (var i in ps) {

        p = ps[i];

        if (m = e.match(p)) {

          // use the Selector.assertions methods unless the selector

          // is too complex.

          if (as[i]) {

            this.tokens.push([i, Object.clone(m)]);

            e = e.replace(m[0], '');

          } else {

            // reluctantly do a document-wide search

            // and look for a match in the array

            return this.findElements(document).include(element);

          }

        }

      }

    }



    var match = true, name, matches;

    for (var i = 0, token; token = this.tokens[i]; i++) {

      name = token[0], matches = token[1];

      if (!Selector.assertions[name](element, matches)) {

        match = false; break;

      }

    }



    return match;

  },



  toString: function() {

    return this.expression;

  },



  inspect: function() {

    return "#<Selector:" + this.expression.inspect() + ">";

  }

});



Object.extend(Selector, {

  _cache: { },



  xpath: {

    descendant:   "//*",

    child:        "/*",

    adjacent:     "/following-sibling::*[1]",

    laterSibling: '/following-sibling::*',

    tagName:      function(m) {

      if (m[1] == '*') return '';

      return "[local-name()='" + m[1].toLowerCase() +

             "' or local-name()='" + m[1].toUpperCase() + "']";

    },

    className:    "[contains(concat(' ', @class, ' '), ' #{1} ')]",

    id:           "[@id='#{1}']",

    attrPresence: function(m) {

      m[1] = m[1].toLowerCase();

      return new Template("[@#{1}]").evaluate(m);

    },

    attr: function(m) {

      m[1] = m[1].toLowerCase();

      m[3] = m[5] || m[6];

      return new Template(Selector.xpath.operators[m[2]]).evaluate(m);

    },

    pseudo: function(m) {

      var h = Selector.xpath.pseudos[m[1]];

      if (!h) return '';

      if (Object.isFunction(h)) return h(m);

      return new Template(Selector.xpath.pseudos[m[1]]).evaluate(m);

    },

    operators: {

      '=':  "[@#{1}='#{3}']",

      '!=': "[@#{1}!='#{3}']",

      '^=': "[starts-with(@#{1}, '#{3}')]",

      '$=': "[substring(@#{1}, (string-length(@#{1}) - string-length('#{3}') + 1))='#{3}']",

      '*=': "[contains(@#{1}, '#{3}')]",

      '~=': "[contains(concat(' ', @#{1}, ' '), ' #{3} ')]",

      '|=': "[contains(concat('-', @#{1}, '-'), '-#{3}-')]"

    },

    pseudos: {

      'first-child': '[not(preceding-sibling::*)]',

      'last-child':  '[not(following-sibling::*)]',

      'only-child':  '[not(preceding-sibling::* or following-sibling::*)]',

      'empty':       "[count(*) = 0 and (count(text()) = 0 or translate(text(), ' \t\r\n', '') = '')]",

      'checked':     "[@checked]",

      'disabled':    "[@disabled]",

      'enabled':     "[not(@disabled)]",

      'not': function(m) {

        var e = m[6], p = Selector.patterns,

            x = Selector.xpath, le, v;



        var exclusion = [];

        while (e && le != e && (/\S/).test(e)) {

          le = e;

          for (var i in p) {

            if (m = e.match(p[i])) {

              v = Object.isFunction(x[i]) ? x[i](m) : new Template(x[i]).evaluate(m);

              exclusion.push("(" + v.substring(1, v.length - 1) + ")");

              e = e.replace(m[0], '');

              break;

            }

          }

        }

        return "[not(" + exclusion.join(" and ") + ")]";

      },

      'nth-child':      function(m) {

        return Selector.xpath.pseudos.nth("(count(./preceding-sibling::*) + 1) ", m);

      },

      'nth-last-child': function(m) {

        return Selector.xpath.pseudos.nth("(count(./following-sibling::*) + 1) ", m);

      },

      'nth-of-type':    function(m) {

        return Selector.xpath.pseudos.nth("position() ", m);

      },

      'nth-last-of-type': function(m) {

        return Selector.xpath.pseudos.nth("(last() + 1 - position()) ", m);

      },

      'first-of-type':  function(m) {

        m[6] = "1"; return Selector.xpath.pseudos['nth-of-type'](m);

      },

      'last-of-type':   function(m) {

        m[6] = "1"; return Selector.xpath.pseudos['nth-last-of-type'](m);

      },

      'only-of-type':   function(m) {

        var p = Selector.xpath.pseudos; return p['first-of-type'](m) + p['last-of-type'](m);

      },

      nth: function(fragment, m) {

        var mm, formula = m[6], predicate;

        if (formula == 'even') formula = '2n+0';

        if (formula == 'odd')  formula = '2n+1';

        if (mm = formula.match(/^(\d+)$/)) // digit only

          return '[' + fragment + "= " + mm[1] + ']';

        if (mm = formula.match(/^(-?\d*)?n(([+-])(\d+))?/)) { // an+b

          if (mm[1] == "-") mm[1] = -1;

          var a = mm[1] ? Number(mm[1]) : 1;

          var b = mm[2] ? Number(mm[2]) : 0;

          predicate = "[((#{fragment} - #{b}) mod #{a} = 0) and " +

          "((#{fragment} - #{b}) div #{a} >= 0)]";

          return new Template(predicate).evaluate({

            fragment: fragment, a: a, b: b });

        }

      }

    }

  },



  criteria: {

    tagName:      'n = h.tagName(n, r, "#{1}", c);      c = false;',

    className:    'n = h.className(n, r, "#{1}", c);    c = false;',

    id:           'n = h.id(n, r, "#{1}", c);           c = false;',

    attrPresence: 'n = h.attrPresence(n, r, "#{1}", c); c = false;',

    attr: function(m) {

      m[3] = (m[5] || m[6]);

      return new Template('n = h.attr(n, r, "#{1}", "#{3}", "#{2}", c); c = false;').evaluate(m);

    },

    pseudo: function(m) {

      if (m[6]) m[6] = m[6].replace(/"/g, '\\"');

      return new Template('n = h.pseudo(n, "#{1}", "#{6}", r, c); c = false;').evaluate(m);

    },

    descendant:   'c = "descendant";',

    child:        'c = "child";',

    adjacent:     'c = "adjacent";',

    laterSibling: 'c = "laterSibling";'

  },



  patterns: {

    // combinators must be listed first

    // (and descendant needs to be last combinator)

    laterSibling: /^\s*~\s*/,

    child:        /^\s*>\s*/,

    adjacent:     /^\s*\+\s*/,

    descendant:   /^\s/,



    // selectors follow

    tagName:      /^\s*(\*|[\w\-]+)(\b|$)?/,

    id:           /^#([\w\-\*]+)(\b|$)/,

    className:    /^\.([\w\-\*]+)(\b|$)/,

    pseudo:

/^:((first|last|nth|nth-last|only)(-child|-of-type)|empty|checked|(en|dis)abled|not)(\((.*?)\))?(\b|$|(?=\s|[:+~>]))/,

    attrPresence: /^\[([\w]+)\]/,

    attr:         /\[((?:[\w-]*:)?[\w-]+)\s*(?:([!^$*~|]?=)\s*((['"])([^\4]*?)\4|([^'"][^\]]*?)))?\]/

  },



  // for Selector.match and Element#match

  assertions: {

    tagName: function(element, matches) {

      return matches[1].toUpperCase() == element.tagName.toUpperCase();

    },



    className: function(element, matches) {

      return Element.hasClassName(element, matches[1]);

    },



    id: function(element, matches) {

      return element.id === matches[1];

    },



    attrPresence: function(element, matches) {

      return Element.hasAttribute(element, matches[1]);

    },



    attr: function(element, matches) {

      var nodeValue = Element.readAttribute(element, matches[1]);

      return nodeValue && Selector.operators[matches[2]](nodeValue, matches[5] || matches[6]);

    }

  },



  handlers: {

    // UTILITY FUNCTIONS

    // joins two collections

    concat: function(a, b) {

      for (var i = 0, node; node = b[i]; i++)

        a.push(node);

      return a;

    },



    // marks an array of nodes for counting

    mark: function(nodes) {

      var _true = Prototype.emptyFunction;

      for (var i = 0, node; node = nodes[i]; i++)

        node._countedByPrototype = _true;

      return nodes;

    },



    unmark: function(nodes) {

      for (var i = 0, node; node = nodes[i]; i++)

        node._countedByPrototype = undefined;

      return nodes;

    },



    // mark each child node with its position (for nth calls)

    // "ofType" flag indicates whether we're indexing for nth-of-type

    // rather than nth-child

    index: function(parentNode, reverse, ofType) {

      parentNode._countedByPrototype = Prototype.emptyFunction;

      if (reverse) {

        for (var nodes = parentNode.childNodes, i = nodes.length - 1, j = 1; i >= 0; i--) {

          var node = nodes[i];

          if (node.nodeType == 1 && (!ofType || node._countedByPrototype)) node.nodeIndex = j++;

        }

      } else {

        for (var i = 0, j = 1, nodes = parentNode.childNodes; node = nodes[i]; i++)

          if (node.nodeType == 1 && (!ofType || node._countedByPrototype)) node.nodeIndex = j++;

      }

    },



    // filters out duplicates and extends all nodes

    unique: function(nodes) {

      if (nodes.length == 0) return nodes;

      var results = [], n;

      for (var i = 0, l = nodes.length; i < l; i++)

        if (!(n = nodes[i])._countedByPrototype) {

          n._countedByPrototype = Prototype.emptyFunction;

          results.push(Element.extend(n));

        }

      return Selector.handlers.unmark(results);

    },



    // COMBINATOR FUNCTIONS

    descendant: function(nodes) {

      var h = Selector.handlers;

      for (var i = 0, results = [], node; node = nodes[i]; i++)

        h.concat(results, node.getElementsByTagName('*'));

      return results;

    },



    child: function(nodes) {

      var h = Selector.handlers;

      for (var i = 0, results = [], node; node = nodes[i]; i++) {

        for (var j = 0, child; child = node.childNodes[j]; j++)

          if (child.nodeType == 1 && child.tagName != '!') results.push(child);

      }

      return results;

    },



    adjacent: function(nodes) {

      for (var i = 0, results = [], node; node = nodes[i]; i++) {

        var next = this.nextElementSibling(node);

        if (next) results.push(next);

      }

      return results;

    },



    laterSibling: function(nodes) {

      var h = Selector.handlers;

      for (var i = 0, results = [], node; node = nodes[i]; i++)

        h.concat(results, Element.nextSiblings(node));

      return results;

    },



    nextElementSibling: function(node) {

      while (node = node.nextSibling)

	      if (node.nodeType == 1) return node;

      return null;

    },



    previousElementSibling: function(node) {

      while (node = node.previousSibling)

        if (node.nodeType == 1) return node;

      return null;

    },



    // TOKEN FUNCTIONS

    tagName: function(nodes, root, tagName, combinator) {

      var uTagName = tagName.toUpperCase();

      var results = [], h = Selector.handlers;

      if (nodes) {

        if (combinator) {

          // fastlane for ordinary descendant combinators

          if (combinator == "descendant") {

            for (var i = 0, node; node = nodes[i]; i++)

              h.concat(results, node.getElementsByTagName(tagName));

            return results;

          } else nodes = this[combinator](nodes);

          if (tagName == "*") return nodes;

        }

        for (var i = 0, node; node = nodes[i]; i++)

          if (node.tagName.toUpperCase() === uTagName) results.push(node);

        return results;

      } else return root.getElementsByTagName(tagName);

    },



    id: function(nodes, root, id, combinator) {

      var targetNode = $(id), h = Selector.handlers;

      if (!targetNode) return [];

      if (!nodes && root == document) return [targetNode];

      if (nodes) {

        if (combinator) {

          if (combinator == 'child') {

            for (var i = 0, node; node = nodes[i]; i++)

              if (targetNode.parentNode == node) return [targetNode];

          } else if (combinator == 'descendant') {

            for (var i = 0, node; node = nodes[i]; i++)

              if (Element.descendantOf(targetNode, node)) return [targetNode];

          } else if (combinator == 'adjacent') {

            for (var i = 0, node; node = nodes[i]; i++)

              if (Selector.handlers.previousElementSibling(targetNode) == node)

                return [targetNode];

          } else nodes = h[combinator](nodes);

        }

        for (var i = 0, node; node = nodes[i]; i++)

          if (node == targetNode) return [targetNode];

        return [];

      }

      return (targetNode && Element.descendantOf(targetNode, root)) ? [targetNode] : [];

    },



    className: function(nodes, root, className, combinator) {

      if (nodes && combinator) nodes = this[combinator](nodes);

      return Selector.handlers.byClassName(nodes, root, className);

    },



    byClassName: function(nodes, root, className) {

      if (!nodes) nodes = Selector.handlers.descendant([root]);

      var needle = ' ' + className + ' ';

      for (var i = 0, results = [], node, nodeClassName; node = nodes[i]; i++) {

        nodeClassName = node.className;

        if (nodeClassName.length == 0) continue;

        if (nodeClassName == className || (' ' + nodeClassName + ' ').include(needle))

          results.push(node);

      }

      return results;

    },



    attrPresence: function(nodes, root, attr, combinator) {

      if (!nodes) nodes = root.getElementsByTagName("*");

      if (nodes && combinator) nodes = this[combinator](nodes);

      var results = [];

      for (var i = 0, node; node = nodes[i]; i++)

        if (Element.hasAttribute(node, attr)) results.push(node);

      return results;

    },



    attr: function(nodes, root, attr, value, operator, combinator) {

      if (!nodes) nodes = root.getElementsByTagName("*");

      if (nodes && combinator) nodes = this[combinator](nodes);

      var handler = Selector.operators[operator], results = [];

      for (var i = 0, node; node = nodes[i]; i++) {

        var nodeValue = Element.readAttribute(node, attr);

        if (nodeValue === null) continue;

        if (handler(nodeValue, value)) results.push(node);

      }

      return results;

    },



    pseudo: function(nodes, name, value, root, combinator) {

      if (nodes && combinator) nodes = this[combinator](nodes);

      if (!nodes) nodes = root.getElementsByTagName("*");

      return Selector.pseudos[name](nodes, value, root);

    }

  },



  pseudos: {

    'first-child': function(nodes, value, root) {

      for (var i = 0, results = [], node; node = nodes[i]; i++) {

        if (Selector.handlers.previousElementSibling(node)) continue;

          results.push(node);

      }

      return results;

    },

    'last-child': function(nodes, value, root) {

      for (var i = 0, results = [], node; node = nodes[i]; i++) {

        if (Selector.handlers.nextElementSibling(node)) continue;

          results.push(node);

      }

      return results;

    },

    'only-child': function(nodes, value, root) {

      var h = Selector.handlers;

      for (var i = 0, results = [], node; node = nodes[i]; i++)

        if (!h.previousElementSibling(node) && !h.nextElementSibling(node))

          results.push(node);


      return results;

    },

    'nth-child':        function(nodes, formula, root) {

      return Selector.pseudos.nth(nodes, formula, root);

    },

    'nth-last-child':   function(nodes, formula, root) {

      return Selector.pseudos.nth(nodes, formula, root, true);

    },

    'nth-of-type':      function(nodes, formula, root) {

      return Selector.pseudos.nth(nodes, formula, root, false, true);

    },

    'nth-last-of-type': function(nodes, formula, root) {

      return Selector.pseudos.nth(nodes, formula, root, true, true);

    },

    'first-of-type':    function(nodes, formula, root) {

      return Selector.pseudos.nth(nodes, "1", root, false, true);

    },

    'last-of-type':     function(nodes, formula, root) {

      return Selector.pseudos.nth(nodes, "1", root, true, true);

    },

    'only-of-type':     function(nodes, formula, root) {

      var p = Selector.pseudos;

      return p['last-of-type'](p['first-of-type'](nodes, formula, root), formula, root);

    },



    // handles the an+b logic

    getIndices: function(a, b, total) {

      if (a == 0) return b > 0 ? [b] : [];

      return $R(1, total).inject([], function(memo, i) {

        if (0 == (i - b) % a && (i - b) / a >= 0) memo.push(i);

        return memo;

      });

    },



    // handles nth(-last)-child, nth(-last)-of-type, and (first|last)-of-type

    nth: function(nodes, formula, root, reverse, ofType) {

      if (nodes.length == 0) return [];

      if (formula == 'even') formula = '2n+0';

      if (formula == 'odd')  formula = '2n+1';

      var h = Selector.handlers, results = [], indexed = [], m;

      h.mark(nodes);

      for (var i = 0, node; node = nodes[i]; i++) {

        if (!node.parentNode._countedByPrototype) {

          h.index(node.parentNode, reverse, ofType);

          indexed.push(node.parentNode);

        }

      }

      if (formula.match(/^\d+$/)) { // just a number

        formula = Number(formula);

        for (var i = 0, node; node = nodes[i]; i++)

          if (node.nodeIndex == formula) results.push(node);

      } else if (m = formula.match(/^(-?\d*)?n(([+-])(\d+))?/)) { // an+b

        if (m[1] == "-") m[1] = -1;

        var a = m[1] ? Number(m[1]) : 1;

        var b = m[2] ? Number(m[2]) : 0;

        var indices = Selector.pseudos.getIndices(a, b, nodes.length);

        for (var i = 0, node, l = indices.length; node = nodes[i]; i++) {

          for (var j = 0; j < l; j++)

            if (node.nodeIndex == indices[j]) results.push(node);

        }

      }

      h.unmark(nodes);

      h.unmark(indexed);

      return results;

    },



    'empty': function(nodes, value, root) {

      for (var i = 0, results = [], node; node = nodes[i]; i++) {

        // IE treats comments as element nodes

        if (node.tagName == '!' || (node.firstChild && !node.innerHTML.match(/^\s*$/))) continue;

        results.push(node);

      }

      return results;

    },



    'not': function(nodes, selector, root) {

      var h = Selector.handlers, selectorType, m;

      var exclusions = new Selector(selector).findElements(root);

      h.mark(exclusions);

      for (var i = 0, results = [], node; node = nodes[i]; i++)

        if (!node._countedByPrototype) results.push(node);

      h.unmark(exclusions);

      return results;

    },



    'enabled': function(nodes, value, root) {

      for (var i = 0, results = [], node; node = nodes[i]; i++)

        if (!node.disabled) results.push(node);

      return results;

    },



    'disabled': function(nodes, value, root) {

      for (var i = 0, results = [], node; node = nodes[i]; i++)

        if (node.disabled) results.push(node);

      return results;

    },



    'checked': function(nodes, value, root) {

      for (var i = 0, results = [], node; node = nodes[i]; i++)

        if (node.checked) results.push(node);

      return results;

    }

  },



  operators: {

    '=':  function(nv, v) { return nv == v; },

    '!=': function(nv, v) { return nv != v; },

    '^=': function(nv, v) { return nv.startsWith(v); },

    '$=': function(nv, v) { return nv.endsWith(v); },

    '*=': function(nv, v) { return nv.include(v); },

    '~=': function(nv, v) { return (' ' + nv + ' ').include(' ' + v + ' '); },

    '|=': function(nv, v) { return ('-' + nv.toUpperCase() + '-').include('-' + v.toUpperCase() + '-'); }

  },



  split: function(expression) {

    var expressions = [];

    expression.scan(/(([\w#:.~>+()\s-]+|\*|\[.*?\])+)\s*(,|$)/, function(m) {

      expressions.push(m[1].strip());

    });

    return expressions;

  },



  matchElements: function(elements, expression) {

    var matches = $$(expression), h = Selector.handlers;

    h.mark(matches);

    for (var i = 0, results = [], element; element = elements[i]; i++)

      if (element._countedByPrototype) results.push(element);

    h.unmark(matches);

    return results;

  },



  findElement: function(elements, expression, index) {

    if (Object.isNumber(expression)) {

      index = expression; expression = false;

    }

    return Selector.matchElements(elements, expression || '*')[index || 0];

  },



  findChildElements: function(element, expressions) {

    expressions = Selector.split(expressions.join(','));

    var results = [], h = Selector.handlers;

    for (var i = 0, l = expressions.length, selector; i < l; i++) {

      selector = new Selector(expressions[i].strip());

      h.concat(results, selector.findElements(element));

    }

    return (l > 1) ? h.unique(results) : results;

  }

});



if (Prototype.Browser.IE) {

  Object.extend(Selector.handlers, {

    // IE returns comment nodes on getElementsByTagName("*").

    // Filter them out.

    concat: function(a, b) {

      for (var i = 0, node; node = b[i]; i++)

        if (node.tagName !== "!") a.push(node);

      return a;

    },



    // IE improperly serializes _countedByPrototype in (inner|outer)HTML.

    unmark: function(nodes) {

      for (var i = 0, node; node = nodes[i]; i++)

        node.removeAttribute('_countedByPrototype');

      return nodes;

    }

  });

}



function $$() {

  return Selector.findChildElements(document, $A(arguments));

}

var Form = {

  reset: function(form) {

    $(form).reset();

    return form;

  },



  serializeElements: function(elements, options) {

    if (typeof options != 'object') options = { hash: !!options };

    else if (Object.isUndefined(options.hash)) options.hash = true;

    var key, value, submitted = false, submit = options.submit;



    var data = elements.inject({ }, function(result, element) {

      if (!element.disabled && element.name) {

        key = element.name; value = $(element).getValue();

        if (value != null && (element.type != 'submit' || (!submitted &&

            submit !== false && (!submit || key == submit) && (submitted = true)))) {

          if (key in result) {

            // a key is already present; construct an array of values

            if (!Object.isArray(result[key])) result[key] = [result[key]];

            result[key].push(value);

          }

          else result[key] = value;

        }

      }

      return result;

    });



    return options.hash ? data : Object.toQueryString(data);

  }

};



Form.Methods = {

  serialize: function(form, options) {

    return Form.serializeElements(Form.getElements(form), options);

  },



  getElements: function(form) {

    return $A($(form).getElementsByTagName('*')).inject([],

      function(elements, child) {

        if (Form.Element.Serializers[child.tagName.toLowerCase()])

          elements.push(Element.extend(child));

        return elements;

      }

    );

  },



  getInputs: function(form, typeName, name) {

    form = $(form);

    var inputs = form.getElementsByTagName('input');



    if (!typeName && !name) return $A(inputs).map(Element.extend);



    for (var i = 0, matchingInputs = [], length = inputs.length; i < length; i++) {

      var input = inputs[i];

      if ((typeName && input.type != typeName) || (name && input.name != name))

        continue;

      matchingInputs.push(Element.extend(input));

    }



    return matchingInputs;

  },



  disable: function(form) {

    form = $(form);

    Form.getElements(form).invoke('disable');

    return form;

  },



  enable: function(form) {

    form = $(form);

    Form.getElements(form).invoke('enable');

    return form;

  },



  findFirstElement: function(form) {

    var elements = $(form).getElements().findAll(function(element) {

      return 'hidden' != element.type && !element.disabled;

    });

    var firstByIndex = elements.findAll(function(element) {

      return element.hasAttribute('tabIndex') && element.tabIndex >= 0;

    }).sortBy(function(element) { return element.tabIndex }).first();



    return firstByIndex ? firstByIndex : elements.find(function(element) {

      return ['input', 'select', 'textarea'].include(element.tagName.toLowerCase());

    });

  },



  focusFirstElement: function(form) {

    form = $(form);

    form.findFirstElement().activate();

    return form;

  },



  request: function(form, options) {

    form = $(form), options = Object.clone(options || { });



    var params = options.parameters, action = form.readAttribute('action') || '';

    if (action.blank()) action = window.location.href;

    options.parameters = form.serialize(true);



    if (params) {

      if (Object.isString(params)) params = params.toQueryParams();

      Object.extend(options.parameters, params);

    }



    if (form.hasAttribute('method') && !options.method)

      options.method = form.method;



    return new Ajax.Request(action, options);

  }

};



/*--------------------------------------------------------------------------*/



Form.Element = {

  focus: function(element) {

    $(element).focus();

    return element;

  },



  select: function(element) {

    $(element).select();

    return element;

  }

};



Form.Element.Methods = {

  serialize: function(element) {

    element = $(element);

    if (!element.disabled && element.name) {

      var value = element.getValue();

      if (value != undefined) {

        var pair = { };

        pair[element.name] = value;

        return Object.toQueryString(pair);

      }

    }

    return '';

  },



  getValue: function(element) {

    element = $(element);

    var method = element.tagName.toLowerCase();

    return Form.Element.Serializers[method](element);

  },



  setValue: function(element, value) {

    element = $(element);

    var method = element.tagName.toLowerCase();

    Form.Element.Serializers[method](element, value);

    return element;

  },



  clear: function(element) {

    $(element).value = '';

    return element;

  },



  present: function(element) {

    return $(element).value != '';

  },



  activate: function(element) {

    element = $(element);

    try {

      element.focus();

      if (element.select && (element.tagName.toLowerCase() != 'input' ||

          !['button', 'reset', 'submit'].include(element.type)))

        element.select();

    } catch (e) { }

    return element;

  },



  disable: function(element) {

    element = $(element);

    element.blur();

    element.disabled = true;

    return element;

  },



  enable: function(element) {

    element = $(element);

    element.disabled = false;

    return element;

  }

};



/*--------------------------------------------------------------------------*/



var Field = Form.Element;

var $F = Form.Element.Methods.getValue;



/*--------------------------------------------------------------------------*/



Form.Element.Serializers = {

  input: function(element, value) {

    switch (element.type.toLowerCase()) {

      case 'checkbox':

      case 'radio':

        return Form.Element.Serializers.inputSelector(element, value);

      default:

        return Form.Element.Serializers.textarea(element, value);

    }

  },



  inputSelector: function(element, value) {

    if (Object.isUndefined(value)) return element.checked ? element.value : null;

    else element.checked = !!value;

  },



  textarea: function(element, value) {

    if (Object.isUndefined(value)) return element.value;

    else element.value = value;

  },



  select: function(element, index) {

    if (Object.isUndefined(index))

      return this[element.type == 'select-one' ?

        'selectOne' : 'selectMany'](element);

    else {

      var opt, value, single = !Object.isArray(index);

      for (var i = 0, length = element.length; i < length; i++) {

        opt = element.options[i];

        value = this.optionValue(opt);

        if (single) {

          if (value == index) {

            opt.selected = true;

            return;

          }

        }

        else opt.selected = index.include(value);

      }

    }

  },



  selectOne: function(element) {

    var index = element.selectedIndex;

    return index >= 0 ? this.optionValue(element.options[index]) : null;

  },



  selectMany: function(element) {

    var values, length = element.length;

    if (!length) return null;



    for (var i = 0, values = []; i < length; i++) {

      var opt = element.options[i];

      if (opt.selected) values.push(this.optionValue(opt));

    }

    return values;

  },



  optionValue: function(opt) {

    // extend element because hasAttribute may not be native

    return Element.extend(opt).hasAttribute('value') ? opt.value : opt.text;

  }

};



/*--------------------------------------------------------------------------*/



Abstract.TimedObserver = Class.create(PeriodicalExecuter, {

  initialize: function($super, element, frequency, callback) {

    $super(callback, frequency);

    this.element   = $(element);

    this.lastValue = this.getValue();

  },



  execute: function() {

    var value = this.getValue();

    if (Object.isString(this.lastValue) && Object.isString(value) ?

        this.lastValue != value : String(this.lastValue) != String(value)) {

      this.callback(this.element, value);

      this.lastValue = value;

    }

  }

});



Form.Element.Observer = Class.create(Abstract.TimedObserver, {

  getValue: function() {

    return Form.Element.getValue(this.element);

  }

});



Form.Observer = Class.create(Abstract.TimedObserver, {

  getValue: function() {

    return Form.serialize(this.element);

  }

});



/*--------------------------------------------------------------------------*/



Abstract.EventObserver = Class.create({

  initialize: function(element, callback) {

    this.element  = $(element);

    this.callback = callback;



    this.lastValue = this.getValue();

    if (this.element.tagName.toLowerCase() == 'form')

      this.registerFormCallbacks();

    else

      this.registerCallback(this.element);

  },



  onElementEvent: function() {

    var value = this.getValue();

    if (this.lastValue != value) {

      this.callback(this.element, value);

      this.lastValue = value;

    }

  },



  registerFormCallbacks: function() {

    Form.getElements(this.element).each(this.registerCallback, this);

  },



  registerCallback: function(element) {

    if (element.type) {

      switch (element.type.toLowerCase()) {

        case 'checkbox':

        case 'radio':

          Event.observe(element, 'click', this.onElementEvent.bind(this));

          break;

        default:

          Event.observe(element, 'change', this.onElementEvent.bind(this));

          break;

      }

    }

  }

});



Form.Element.EventObserver = Class.create(Abstract.EventObserver, {

  getValue: function() {

    return Form.Element.getValue(this.element);

  }

});



Form.EventObserver = Class.create(Abstract.EventObserver, {

  getValue: function() {

    return Form.serialize(this.element);

  }

});

if (!window.Event) var Event = { };



Object.extend(Event, {

  KEY_BACKSPACE: 8,

  KEY_TAB:       9,

  KEY_RETURN:   13,

  KEY_ESC:      27,

  KEY_LEFT:     37,

  KEY_UP:       38,

  KEY_RIGHT:    39,

  KEY_DOWN:     40,

  KEY_DELETE:   46,

  KEY_HOME:     36,

  KEY_END:      35,

  KEY_PAGEUP:   33,

  KEY_PAGEDOWN: 34,

  KEY_INSERT:   45,



  cache: { },



  relatedTarget: function(event) {

    var element;

    switch(event.type) {

      case 'mouseover': element = event.fromElement; break;

      case 'mouseout':  element = event.toElement;   break;

      default: return null;

    }

    return Element.extend(element);

  }

});



Event.Methods = (function() {

  var isButton;



  if (Prototype.Browser.IE) {

    var buttonMap = { 0: 1, 1: 4, 2: 2 };

    isButton = function(event, code) {

      return event.button == buttonMap[code];

    };



  } else if (Prototype.Browser.WebKit) {

    isButton = function(event, code) {

      switch (code) {

        case 0: return event.which == 1 && !event.metaKey;

        case 1: return event.which == 1 && event.metaKey;

        default: return false;

      }

    };



  } else {

    isButton = function(event, code) {

      return event.which ? (event.which === code + 1) : (event.button === code);

    };

  }



  return {

    isLeftClick:   function(event) { return isButton(event, 0) },

    isMiddleClick: function(event) { return isButton(event, 1) },

    isRightClick:  function(event) { return isButton(event, 2) },



    element: function(event) {

      var node = Event.extend(event).target;

      return Element.extend(node.nodeType == Node.TEXT_NODE ? node.parentNode : node);

    },



    findElement: function(event, expression) {

      var element = Event.element(event);

      if (!expression) return element;

      var elements = [element].concat(element.ancestors());

      return Selector.findElement(elements, expression, 0);

    },



    pointer: function(event) {

      return {

        x: event.pageX || (event.clientX +

          (document.documentElement.scrollLeft || document.body.scrollLeft)),

        y: event.pageY || (event.clientY +

          (document.documentElement.scrollTop || document.body.scrollTop))

      };

    },



    pointerX: function(event) { return Event.pointer(event).x },

    pointerY: function(event) { return Event.pointer(event).y },



    stop: function(event) {

      Event.extend(event);

      event.preventDefault();

      event.stopPropagation();

      event.stopped = true;

    }

  };

})();



Event.extend = (function() {

  var methods = Object.keys(Event.Methods).inject({ }, function(m, name) {

    m[name] = Event.Methods[name].methodize();

    return m;

  });



  if (Prototype.Browser.IE) {

    Object.extend(methods, {

      stopPropagation: function() { this.cancelBubble = true },

      preventDefault:  function() { this.returnValue = false },

      inspect: function() { return "[object Event]" }

    });



    return function(event) {

      if (!event) return false;

      if (event._extendedByPrototype) return event;



      event._extendedByPrototype = Prototype.emptyFunction;

      var pointer = Event.pointer(event);

      Object.extend(event, {

        target: event.srcElement,

        relatedTarget: Event.relatedTarget(event),

        pageX:  pointer.x,

        pageY:  pointer.y

      });

      return Object.extend(event, methods);

    };



  } else {

    Event.prototype = Event.prototype || document.createEvent("HTMLEvents").__proto__;

    Object.extend(Event.prototype, methods);

    return Prototype.K;

  }

})();



Object.extend(Event, (function() {

  var cache = Event.cache;



  function getEventID(element) {

    if (element._prototypeEventID) return element._prototypeEventID[0];

    arguments.callee.id = arguments.callee.id || 1;

    return element._prototypeEventID = [++arguments.callee.id];

  }



  function getDOMEventName(eventName) {

    if (eventName && eventName.include(':')) return "dataavailable";

    return eventName;

  }



  function getCacheForID(id) {

    return cache[id] = cache[id] || { };

  }



  function getWrappersForEventName(id, eventName) {

    var c = getCacheForID(id);

    return c[eventName] = c[eventName] || [];

  }



  function createWrapper(element, eventName, handler) {

    var id = getEventID(element);

    var c = getWrappersForEventName(id, eventName);

    if (c.pluck("handler").include(handler)) return false;



    var wrapper = function(event) {

      if (!Event || !Event.extend ||

        (event.eventName && event.eventName != eventName))

          return false;



      Event.extend(event);

      handler.call(element, event);

    };



    wrapper.handler = handler;

    c.push(wrapper);

    return wrapper;

  }



  function findWrapper(id, eventName, handler) {

    var c = getWrappersForEventName(id, eventName);

    return c.find(function(wrapper) { return wrapper.handler == handler });

  }



  function destroyWrapper(id, eventName, handler) {

    var c = getCacheForID(id);

    if (!c[eventName]) return false;

    c[eventName] = c[eventName].without(findWrapper(id, eventName, handler));

  }



  function destroyCache() {

    for (var id in cache)

      for (var eventName in cache[id])

        cache[id][eventName] = null;

  }



  if (window.attachEvent) {

    window.attachEvent("onunload", destroyCache);

  }



  return {

    observe: function(element, eventName, handler) {

      element = $(element);

      var name = getDOMEventName(eventName);



      var wrapper = createWrapper(element, eventName, handler);

      if (!wrapper) return element;



      if (element.addEventListener) {

        element.addEventListener(name, wrapper, false);

      } else {

        element.attachEvent("on" + name, wrapper);

      }



      return element;

    },



    stopObserving: function(element, eventName, handler) {

      element = $(element);

      var id = getEventID(element), name = getDOMEventName(eventName);



      if (!handler && eventName) {

        getWrappersForEventName(id, eventName).each(function(wrapper) {

          element.stopObserving(eventName, wrapper.handler);

        });

        return element;



      } else if (!eventName) {

        Object.keys(getCacheForID(id)).each(function(eventName) {

          element.stopObserving(eventName);

        });

        return element;

      }



      var wrapper = findWrapper(id, eventName, handler);

      if (!wrapper) return element;



      if (element.removeEventListener) {

        element.removeEventListener(name, wrapper, false);

      } else {

        element.detachEvent("on" + name, wrapper);

      }



      destroyWrapper(id, eventName, handler);



      return element;

    },



    fire: function(element, eventName, memo) {

      element = $(element);

      if (element == document && document.createEvent && !element.dispatchEvent)

        element = document.documentElement;



      var event;

      if (document.createEvent) {

        event = document.createEvent("HTMLEvents");

        event.initEvent("dataavailable", true, true);

      } else {

        event = document.createEventObject();

        event.eventType = "ondataavailable";

      }



      event.eventName = eventName;

      event.memo = memo || { };



      if (document.createEvent) {

        element.dispatchEvent(event);

      } else {

        element.fireEvent(event.eventType, event);

      }



      return Event.extend(event);

    }

  };

})());



Object.extend(Event, Event.Methods);



Element.addMethods({

  fire:          Event.fire,

  observe:       Event.observe,

  stopObserving: Event.stopObserving

});



Object.extend(document, {

  fire:          Element.Methods.fire.methodize(),

  observe:       Element.Methods.observe.methodize(),

  stopObserving: Element.Methods.stopObserving.methodize(),

  loaded:        false

});



(function() {

  /* Support for the DOMContentLoaded event is based on work by Dan Webb,

     Matthias Miller, Dean Edwards and John Resig. */



  var timer;



  function fireContentLoadedEvent() {

    if (document.loaded) return;

    if (timer) window.clearInterval(timer);

    document.fire("dom:loaded");

    document.loaded = true;

  }



  if (document.addEventListener) {

    if (Prototype.Browser.WebKit) {

      timer = window.setInterval(function() {

        if (/loaded|complete/.test(document.readyState))

          fireContentLoadedEvent();

      }, 0);



      Event.observe(window, "load", fireContentLoadedEvent);



    } else {

      document.addEventListener("DOMContentLoaded",

        fireContentLoadedEvent, false);

    }



  } else {

    document.write("<script id=__onDOMContentLoaded defer src=//:><\/script>");

    $("__onDOMContentLoaded").onreadystatechange = function() {

      if (this.readyState == "complete") {

        this.onreadystatechange = null;

        fireContentLoadedEvent();

      }

    };

  }

})();

/*------------------------------- DEPRECATED -------------------------------*/



Hash.toQueryString = Object.toQueryString;



var Toggle = { display: Element.toggle };



Element.Methods.childOf = Element.Methods.descendantOf;



var Insertion = {

  Before: function(element, content) {

    return Element.insert(element, {before:content});

  },



  Top: function(element, content) {

    return Element.insert(element, {top:content});

  },



  Bottom: function(element, content) {

    return Element.insert(element, {bottom:content});

  },



  After: function(element, content) {

    return Element.insert(element, {after:content});

  }

};



var $continue = new Error('"throw $continue" is deprecated, use "return" instead');



// This should be moved to script.aculo.us; notice the deprecated methods

// further below, that map to the newer Element methods.

var Position = {

  // set to true if needed, warning: firefox performance problems

  // NOT neeeded for page scrolling, only if draggable contained in

  // scrollable elements

  includeScrollOffsets: false,



  // must be called before calling withinIncludingScrolloffset, every time the

  // page is scrolled

  prepare: function() {

    this.deltaX =  window.pageXOffset

                || document.documentElement.scrollLeft

                || document.body.scrollLeft

                || 0;

    this.deltaY =  window.pageYOffset

                || document.documentElement.scrollTop

                || document.body.scrollTop

                || 0;

  },



  // caches x/y coordinate pair to use with overlap

  within: function(element, x, y) {

    if (this.includeScrollOffsets)

      return this.withinIncludingScrolloffsets(element, x, y);

    this.xcomp = x;

    this.ycomp = y;

    this.offset = Element.cumulativeOffset(element);



    return (y >= this.offset[1] &&

            y <  this.offset[1] + element.offsetHeight &&

            x >= this.offset[0] &&

            x <  this.offset[0] + element.offsetWidth);

  },



  withinIncludingScrolloffsets: function(element, x, y) {

    var offsetcache = Element.cumulativeScrollOffset(element);



    this.xcomp = x + offsetcache[0] - this.deltaX;

    this.ycomp = y + offsetcache[1] - this.deltaY;

    this.offset = Element.cumulativeOffset(element);



    return (this.ycomp >= this.offset[1] &&

            this.ycomp <  this.offset[1] + element.offsetHeight &&

            this.xcomp >= this.offset[0] &&

            this.xcomp <  this.offset[0] + element.offsetWidth);

  },



  // within must be called directly before

  overlap: function(mode, element) {

    if (!mode) return 0;

    if (mode == 'vertical')

      return ((this.offset[1] + element.offsetHeight) - this.ycomp) /

        element.offsetHeight;

    if (mode == 'horizontal')

      return ((this.offset[0] + element.offsetWidth) - this.xcomp) /

        element.offsetWidth;

  },



  // Deprecation layer -- use newer Element methods now (1.5.2).



  cumulativeOffset: Element.Methods.cumulativeOffset,



  positionedOffset: Element.Methods.positionedOffset,



  absolutize: function(element) {

    Position.prepare();

    return Element.absolutize(element);

  },



  relativize: function(element) {

    Position.prepare();

    return Element.relativize(element);

  },



  realOffset: Element.Methods.cumulativeScrollOffset,



  offsetParent: Element.Methods.getOffsetParent,



  page: Element.Methods.viewportOffset,



  clone: function(source, target, options) {

    options = options || { };

    return Element.clonePosition(target, source, options);

  }

};



/*--------------------------------------------------------------------------*/



if (!document.getElementsByClassName) document.getElementsByClassName = function(instanceMethods){

  function iter(name) {

    return name.blank() ? null : "[contains(concat(' ', @class, ' '), ' " + name + " ')]";

  }



  instanceMethods.getElementsByClassName = Prototype.BrowserFeatures.XPath ?

  function(element, className) {

    className = className.toString().strip();

    var cond = /\s/.test(className) ? $w(className).map(iter).join('') : iter(className);

    return cond ? document._getElementsByXPath('.//*' + cond, element) : [];

  } : function(element, className) {

    className = className.toString().strip();

    var elements = [], classNames = (/\s/.test(className) ? $w(className) : null);

    if (!classNames && !className) return elements;



    var nodes = $(element).getElementsByTagName('*');

    className = ' ' + className + ' ';



    for (var i = 0, child, cn; child = nodes[i]; i++) {

      if (child.className && (cn = ' ' + child.className + ' ') && (cn.include(className) ||

          (classNames && classNames.all(function(name) {

            return !name.toString().blank() && cn.include(' ' + name + ' ');

          }))))

        elements.push(Element.extend(child));

    }

    return elements;

  };



  return function(className, parentElement) {

    return $(parentElement || document.body).getElementsByClassName(className);

  };

}(Element.Methods);



/*--------------------------------------------------------------------------*/



Element.ClassNames = Class.create();

Element.ClassNames.prototype = {

  initialize: function(element) {

    this.element = $(element);

  },



  _each: function(iterator) {

    this.element.className.split(/\s+/).select(function(name) {

      return name.length > 0;

    })._each(iterator);

  },



  set: function(className) {

    this.element.className = className;

  },



  add: function(classNameToAdd) {

    if (this.include(classNameToAdd)) return;

    this.set($A(this).concat(classNameToAdd).join(' '));

  },



  remove: function(classNameToRemove) {

    if (!this.include(classNameToRemove)) return;

    this.set($A(this).without(classNameToRemove).join(' '));

  },



  toString: function() {

    return $A(this).join(' ');

  }

};



Object.extend(Element.ClassNames.prototype, Enumerable);



/*--------------------------------------------------------------------------*/



Element.addMethods();