text: YUI.add('yui2-selector', function(Y) {
      var YAHOO    = Y.YUI2;
      /*
  Copyright (c) 2011, Yahoo! Inc. All rights reserved.
  Code licensed under the BSD License:
  http://developer.yahoo.com/yui/license.html
  version: 2.9.0
  */
  var Y = YAHOO,
      Y_DOM = YAHOO.util.Dom, 
      EMPTY_ARRAY = [],
      Y_UA = Y.env.ua,
      Y_Lang = Y.lang,
      Y_DOC = document,
      Y_DOCUMENT_ELEMENT = Y_DOC.documentElement,
  
      Y_DOM_inDoc = Y_DOM.inDocument, 
      Y_mix = Y_Lang.augmentObject,
      Y_guid = Y_DOM.generateId,
  
      Y_getDoc = function(element) {
          var doc = Y_DOC;
          if (element) {
              doc = (element.nodeType === 9) ? element : // element === document
                  element.ownerDocument || // element === DOM node
                  element.document || // element === window
                  Y_DOC; // default
          }
  
          return doc;
      },
      
      Y_Array = function(o, startIdx) {
          var l, a, start = startIdx || 0;
  
          // IE errors when trying to slice HTMLElement collections
          try {
              return Array.prototype.slice.call(o, start);
          } catch (e) {
              a = [];
              l = o.length;
              for (; start < l; start++) {
                  a.push(o[start]);
              }
              return a;
          }
      },
  
      Y_DOM_allById = function(id, root) {
          root = root || Y_DOC;
          var nodes = [],
              ret = [],
              i,
              node;
  
          if (root.querySelectorAll) {
              ret = root.querySelectorAll('[id="' + id + '"]');
          } else if (root.all) {
              nodes = root.all(id);
  
              if (nodes) {
                  // root.all may return HTMLElement or HTMLCollection.
                  // some elements are also HTMLCollection (FORM, SELECT).
                  if (nodes.nodeName) {
                      if (nodes.id === id) { // avoid false positive on name
                          ret.push(nodes);
                          nodes = EMPTY_ARRAY; // done, no need to filter
                      } else { //  prep for filtering
                          nodes = [nodes];
                      }
                  }
  
                  if (nodes.length) {
                      // filter out matches on node.name
                      // and element.id as reference to element with id === 'id'
                      for (i = 0; node = nodes[i++];) {
                          if (node.id === id  || 
                                  (node.attributes && node.attributes.id &&
                                  node.attributes.id.value === id)) { 
                              ret.push(node);
                          }
                      }
                  }
              }
          } else {
              ret = [Y_getDoc(root).getElementById(id)];
          }
  
          return ret;
      };
  
  /**
   * The selector-native module provides support for native querySelector
   * @module dom
   * @submodule selector-native
   * @for Selector
   */
  
  /**
   * Provides support for using CSS selectors to query the DOM 
   * @class Selector 
   * @static
   * @for Selector
   */
  
  var COMPARE_DOCUMENT_POSITION = 'compareDocumentPosition',
      OWNER_DOCUMENT = 'ownerDocument',
  
  Selector = {
      _foundCache: [],
  
      useNative: true,
  
      _compare: ('sourceIndex' in Y_DOCUMENT_ELEMENT) ?
          function(nodeA, nodeB) {
              var a = nodeA.sourceIndex,
                  b = nodeB.sourceIndex;
  
              if (a === b) {
                  return 0;
              } else if (a > b) {
                  return 1;
              }
  
              return -1;
  
          } : (Y_DOCUMENT_ELEMENT[COMPARE_DOCUMENT_POSITION] ?
          function(nodeA, nodeB) {
              if (nodeA[COMPARE_DOCUMENT_POSITION](nodeB) & 4) {
                  return -1;
              } else {
                  return 1;
              }
          } :
          function(nodeA, nodeB) {
              var rangeA, rangeB, compare;
              if (nodeA && nodeB) {
                  rangeA = nodeA[OWNER_DOCUMENT].createRange();
                  rangeA.setStart(nodeA, 0);
                  rangeB = nodeB[OWNER_DOCUMENT].createRange();
                  rangeB.setStart(nodeB, 0);
                  compare = rangeA.compareBoundaryPoints(1, rangeB); // 1 === Range.START_TO_END
              }
  
              return compare;
          
      }),
  
      _sort: function(nodes) {
          if (nodes) {
              nodes = Y_Array(nodes, 0, true);
              if (nodes.sort) {
                  nodes.sort(Selector._compare);
              }
          }
  
          return nodes;
      },
  
      _deDupe: function(nodes) {
          var ret = [],
              i, node;
  
          for (i = 0; (node = nodes[i++]);) {
              if (!node._found) {
                  ret[ret.length] = node;
                  node._found = true;
              }
          }
  
          for (i = 0; (node = ret[i++]);) {
              node._found = null;
              node.removeAttribute('_found');
          }
  
          return ret;
      },
  
      /**
       * Retrieves a set of nodes based on a given CSS selector. 
       * @method query
       *
       * @param {string} selector The CSS Selector to test the node against.
       * @param {HTMLElement} root optional An HTMLElement to start the query from. Defaults to Y.config.doc
       * @param {Boolean} firstOnly optional Whether or not to return only the first match.
       * @return {Array} An array of nodes that match the given selector.
       * @static
       */
      query: function(selector, root, firstOnly, skipNative) {
          if (root && typeof root == 'string') {
              root = Y_DOM.get(root);
              if (!root) {
                  return (firstOnly) ? null : [];
              }
          } else {
              root = root || Y_DOC;
          }
  
          var ret = [],
              useNative = (Selector.useNative && Y_DOC.querySelector && !skipNative),
              queries = [[selector, root]],
              query,
              result,
              i,
              fn = (useNative) ? Selector._nativeQuery : Selector._bruteQuery;
  
          if (selector && fn) {
              // split group into seperate queries
              if (!skipNative && // already done if skipping
                      (!useNative || root.tagName)) { // split native when element scoping is needed
                  queries = Selector._splitQueries(selector, root);
              }
  
              for (i = 0; (query = queries[i++]);) {
                  result = fn(query[0], query[1], firstOnly);
                  if (!firstOnly) { // coerce DOM Collection to Array
                      result = Y_Array(result, 0, true);
                  }
                  if (result) {
                      ret = ret.concat(result);
                  }
              }
  
              if (queries.length > 1) { // remove dupes and sort by doc order 
                  ret = Selector._sort(Selector._deDupe(ret));
              }
          }
  
          YAHOO.log('query: ' + selector + ' returning: ' + ret.length, 'info', 'Selector');
          return (firstOnly) ? (ret[0] || null) : ret;
  
      },
  
      // allows element scoped queries to begin with combinator
      // e.g. query('> p', document.body) === query('body > p')
      _splitQueries: function(selector, node) {
          var groups = selector.split(','),
              queries = [],
              prefix = '',
              i, len;
  
          if (node) {
              // enforce for element scoping
              if (node.tagName) {
                  node.id = node.id || Y_guid();
                  prefix = '[id="' + node.id + '"] ';
              }
  
              for (i = 0, len = groups.length; i < len; ++i) {
                  selector =  prefix + groups[i];
                  queries.push([selector, node]);
              }
          }
  
          return queries;
      },
  
      _nativeQuery: function(selector, root, one) {
          if (Y_UA.webkit && selector.indexOf(':checked') > -1 &&
                  (Selector.pseudos && Selector.pseudos.checked)) { // webkit (chrome, safari) fails to find "selected"
              return Selector.query(selector, root, one, true); // redo with skipNative true to try brute query
          }
          try {
              //YAHOO.log('trying native query with: ' + selector, 'info', 'selector-native');
              return root['querySelector' + (one ? '' : 'All')](selector);
          } catch(e) { // fallback to brute if available
              //YAHOO.log('native query error; reverting to brute query with: ' + selector, 'info', 'selector-native');
              return Selector.query(selector, root, one, true); // redo with skipNative true
          }
      },
  
      filter: function(nodes, selector) {
          var ret = [],
              i, node;
  
          if (nodes && selector) {
              for (i = 0; (node = nodes[i++]);) {
                  if (Selector.test(node, selector)) {
                      ret[ret.length] = node;
                  }
              }
          } else {
              YAHOO.log('invalid filter input (nodes: ' + nodes +
                      ', selector: ' + selector + ')', 'warn', 'Selector');
          }
  
          return ret;
      },
  
      test: function(node, selector, root) {
          var ret = false,
              groups = selector.split(','),
              useFrag = false,
              parent,
              item,
              items,
              frag,
              i, j, group;
  
          if (node && node.tagName) { // only test HTMLElements
  
              // we need a root if off-doc
              if (!root && !Y_DOM_inDoc(node)) {
                  parent = node.parentNode;
                  if (parent) { 
                      root = parent;
                  } else { // only use frag when no parent to query
                      frag = node[OWNER_DOCUMENT].createDocumentFragment();
                      frag.appendChild(node);
                      root = frag;
                      useFrag = true;
                  }
              }
              root = root || node[OWNER_DOCUMENT];
  
              if (!node.id) {
                  node.id = Y_guid();
              }
              for (i = 0; (group = groups[i++]);) { // TODO: off-dom test
                  group += '[id="' + node.id + '"]';
                  items = Selector.query(group, root);
  
                  for (j = 0; item = items[j++];) {
                      if (item === node) {
                          ret = true;
                          break;
                      }
                  }
                  if (ret) {
                      break;
                  }
              }
  
              if (useFrag) { // cleanup
                  frag.removeChild(node);
              }
          }
  
          return ret;
      }
  
  };
  
  YAHOO.util.Selector = Selector;
  /**
   * The selector module provides helper methods allowing CSS2 Selectors to be used with DOM elements.
   * @module dom
   * @submodule selector-css2
   * @for Selector
   */
  
  /**
   * Provides helper methods for collecting and filtering DOM elements.
   */
  
  var PARENT_NODE = 'parentNode',
      TAG_NAME = 'tagName',
      ATTRIBUTES = 'attributes',
      COMBINATOR = 'combinator',
      PSEUDOS = 'pseudos',
  
      SelectorCSS2 = {
          _reRegExpTokens: /([\^\$\?\[\]\*\+\-\.\(\)\|\\])/, // TODO: move?
          SORT_RESULTS: true,
          _children: function(node, tag) {
              var ret = node.children,
                  i,
                  children = [],
                  childNodes,
                  child;
  
              if (node.children && tag && node.children.tags) {
                  children = node.children.tags(tag);
              } else if ((!ret && node[TAG_NAME]) || (ret && tag)) { // only HTMLElements have children
                  childNodes = ret || node.childNodes;
                  ret = [];
                  for (i = 0; (child = childNodes[i++]);) {
                      if (child.tagName) {
                          if (!tag || tag === child.tagName) {
                              ret.push(child);
                          }
                      }
                  }
              }
  
              return ret || [];
          },
  
          _re: {
              //attr: /(\[.*\])/g,
              attr: /(\[[^\]]*\])/g,
              //esc: /\\[:\[][\w\d\]]*/gi,
              esc: /\\[:\[\]\(\)#\.\'\>+~"]/gi,
              //pseudos: /:([\-\w]+(?:\(?:['"]?(.+)['"]?\))*)/i
              pseudos: /(\([^\)]*\))/g
          },
  
          /**
           * Mapping of shorthand tokens to corresponding attribute selector 
           * @property shorthand
           * @type object
           */
          shorthand: {
              //'\\#([^\\s\\\\(\\[:]*)': '[id=$1]',
              '\\#(-?[_a-z]+[-\\w\\uE000]*)': '[id=$1]',
              //'\\#([^\\s\\\.:\\[\\]]*)': '[id=$1]',
              //'\\.([^\\s\\\\(\\[:]*)': '[className=$1]'
              '\\.(-?[_a-z]+[-\\w\\uE000]*)': '[className~=$1]'
          },
  
          /**
           * List of operators and corresponding boolean functions. 
           * These functions are passed the attribute and the current node's value of the attribute.
           * @property operators
           * @type object
           */
          operators: {
              '': function(node, attr) { return !!node.getAttribute(attr); }, // Just test for existence of attribute
              //'': '.+',
              //'=': '^{val}$', // equality
              '~=': '(?:^|\\s+){val}(?:\\s+|$)', // space-delimited
              '|=': '^{val}(?:-|$)' // optional hyphen-delimited
          },
  
          pseudos: {
             'first-child': function(node) { 
                  return Selector._children(node[PARENT_NODE])[0] === node; 
              } 
          },
  
          _bruteQuery: function(selector, root, firstOnly) {
              var ret = [],
                  nodes = [],
                  tokens = Selector._tokenize(selector),
                  token = tokens[tokens.length - 1],
                  rootDoc = Y_getDoc(root),
                  child,
                  id,
                  className,
                  tagName;
  
  
              // if we have an initial ID, set to root when in document
              /*
              if (tokens[0] && rootDoc === root &&  
                      (id = tokens[0].id) &&
                      rootDoc.getElementById(id)) {
                  root = rootDoc.getElementById(id);
              }
              */
  
              if (token) {
                  // prefilter nodes
                  id = token.id;
                  className = token.className;
                  tagName = token.tagName || '*';
  
                  if (root.getElementsByTagName) { // non-IE lacks DOM api on doc frags
                      // try ID first, unless no root.all && root not in document
                      // (root.all works off document, but not getElementById)
                      // TODO: move to allById?
                      if (id && (root.all || (root.nodeType === 9 || Y_DOM_inDoc(root)))) {
                          nodes = Y_DOM_allById(id, root);
                      // try className
                      } else if (className) {
                          nodes = root.getElementsByClassName(className);
                      } else { // default to tagName
                          nodes = root.getElementsByTagName(tagName);
                      }
  
                  } else { // brute getElementsByTagName('*')
                      child = root.firstChild;
                      while (child) {
                          if (child.tagName) { // only collect HTMLElements
                              nodes.push(child);
                          }
                          child = child.nextSilbing || child.firstChild;
                      }
                  }
                  if (nodes.length) {
                      ret = Selector._filterNodes(nodes, tokens, firstOnly);
                  }
              }
  
              return ret;
          },
          
          _filterNodes: function(nodes, tokens, firstOnly) {
              var i = 0,
                  j,
                  len = tokens.length,
                  n = len - 1,
                  result = [],
                  node = nodes[0],
                  tmpNode = node,
                  getters = Selector.getters,
                  operator,
                  combinator,
                  token,
                  path,
                  pass,
                  //FUNCTION = 'function',
                  value,
                  tests,
                  test;
  
              //do {
              for (i = 0; (tmpNode = node = nodes[i++]);) {
                  n = len - 1;
                  path = null;
                  
                  testLoop:
                  while (tmpNode && tmpNode.tagName) {
                      token = tokens[n];
                      tests = token.tests;
                      j = tests.length;
                      if (j && !pass) {
                          while ((test = tests[--j])) {
                              operator = test[1];
                              if (getters[test[0]]) {
                                  value = getters[test[0]](tmpNode, test[0]);
                              } else {
                                  value = tmpNode[test[0]];
                                  // use getAttribute for non-standard attributes
                                  if (value === undefined && tmpNode.getAttribute) {
                                      value = tmpNode.getAttribute(test[0]);
                                  }
                              }
  
                              if ((operator === '=' && value !== test[2]) ||  // fast path for equality
                                  (typeof operator !== 'string' && // protect against String.test monkey-patch (Moo)
                                  operator.test && !operator.test(value)) ||  // regex test
                                  (!operator.test && // protect against RegExp as function (webkit)
                                          typeof operator === 'function' && !operator(tmpNode, test[0], test[2]))) { // function test
  
                                  // skip non element nodes or non-matching tags
                                  if ((tmpNode = tmpNode[path])) {
                                      while (tmpNode &&
                                          (!tmpNode.tagName ||
                                              (token.tagName && token.tagName !== tmpNode.tagName))
                                      ) {
                                          tmpNode = tmpNode[path]; 
                                      }
                                  }
                                  continue testLoop;
                              }
                          }
                      }
  
                      n--; // move to next token
                      // now that we've passed the test, move up the tree by combinator
                      if (!pass && (combinator = token.combinator)) {
                          path = combinator.axis;
                          tmpNode = tmpNode[path];
  
                          // skip non element nodes
                          while (tmpNode && !tmpNode.tagName) {
                              tmpNode = tmpNode[path]; 
                          }
  
                          if (combinator.direct) { // one pass only
                              path = null; 
                          }
  
                      } else { // success if we made it this far
                          result.push(node);
                          if (firstOnly) {
                              return result;
                          }
                          break;
                      }
                  }
              }// while (tmpNode = node = nodes[++i]);
              node = tmpNode = null;
              return result;
          },
  
          combinators: {
              ' ': {
                  axis: 'parentNode'
              },
  
              '>': {
                  axis: 'parentNode',
                  direct: true
              },
  
  
              '+': {
                  axis: 'previousSibling',
                  direct: true
              }
          },
  
          _parsers: [
              {
                  name: ATTRIBUTES,
                  //re: /^\[(-?[a-z]+[\w\-]*)+([~\|\^\$\*!=]=?)?['"]?([^\]]*?)['"]?\]/i,
                  re: /^\uE003(-?[a-z]+[\w\-]*)+([~\|\^\$\*!=]=?)?['"]?([^\uE004'"]*)['"]?\uE004/i,
                  fn: function(match, token) {
                      var operator = match[2] || '',
                          operators = Selector.operators,
                          escVal = (match[3]) ? match[3].replace(/\\/g, '') : '',
                          test;
  
                      // add prefiltering for ID and CLASS
                      if ((match[1] === 'id' && operator === '=') ||
                              (match[1] === 'className' &&
                              Y_DOCUMENT_ELEMENT.getElementsByClassName &&
                              (operator === '~=' || operator === '='))) {
                          token.prefilter = match[1];
  
  
                          match[3] = escVal; 
  
                          // escape all but ID for prefilter, which may run through QSA (via Dom.allById)
                          token[match[1]] = (match[1] === 'id') ? match[3] : escVal;
  
                      }
  
                      // add tests
                      if (operator in operators) {
                          test = operators[operator];
                          if (typeof test === 'string') {
                              match[3] = escVal.replace(Selector._reRegExpTokens, '\\$1');
                              test = new RegExp(test.replace('{val}', match[3]));
                          }
                          match[2] = test;
                      }
                      if (!token.last || token.prefilter !== match[1]) {
                          return match.slice(1);
                      }
                  }
  
              },
              {
                  name: TAG_NAME,
                  re: /^((?:-?[_a-z]+[\w-]*)|\*)/i,
                  fn: function(match, token) {
                      var tag = match[1].toUpperCase();
                      token.tagName = tag;
  
                      if (tag !== '*' && (!token.last || token.prefilter)) {
                          return [TAG_NAME, '=', tag];
                      }
                      if (!token.prefilter) {
                          token.prefilter = 'tagName';
                      }
                  }
              },
              {
                  name: COMBINATOR,
                  re: /^\s*([>+~]|\s)\s*/,
                  fn: function(match, token) {
                  }
              },
              {
                  name: PSEUDOS,
                  re: /^:([\-\w]+)(?:\uE005['"]?([^\uE005]*)['"]?\uE006)*/i,
                  fn: function(match, token) {
                      var test = Selector[PSEUDOS][match[1]];
                      if (test) { // reorder match array and unescape special chars for tests
                          if (match[2]) {
                              match[2] = match[2].replace(/\\/g, '');
                          }
                          return [match[2], test]; 
                      } else { // selector token not supported (possibly missing CSS3 module)
                          return false;
                      }
                  }
              }
              ],
  
          _getToken: function(token) {
              return {
                  tagName: null,
                  id: null,
                  className: null,
                  attributes: {},
                  combinator: null,
                  tests: []
              };
          },
  
          /**
              Break selector into token units per simple selector.
              Combinator is attached to the previous token.
           */
          _tokenize: function(selector) {
              selector = selector || '';
              selector = Selector._replaceShorthand(Y_Lang.trim(selector)); 
              var token = Selector._getToken(),     // one token per simple selector (left selector holds combinator)
                  query = selector, // original query for debug report
                  tokens = [],    // array of tokens
                  found = false,  // whether or not any matches were found this pass
                  match,         // the regex match
                  test,
                  i, parser;
  
              /*
                  Search for selector patterns, store, and strip them from the selector string
                  until no patterns match (invalid selector) or we run out of chars.
  
                  Multiple attributes and pseudos are allowed, in any order.
                  for example:
                      'form:first-child[type=button]:not(button)[lang|=en]'
              */
  
              outer:
              do {
                  found = false; // reset after full pass
  
                  for (i = 0; (parser = Selector._parsers[i++]);) {
                      if ( (match = parser.re.exec(selector)) ) { // note assignment
                          if (parser.name !== COMBINATOR ) {
                              token.selector = selector;
                          }
                          selector = selector.replace(match[0], ''); // strip current match from selector
                          if (!selector.length) {
                              token.last = true;
                          }
  
                          if (Selector._attrFilters[match[1]]) { // convert class to className, etc.
                              match[1] = Selector._attrFilters[match[1]];
                          }
  
                          test = parser.fn(match, token);
                          if (test === false) { // selector not supported
                              found = false;
                              break outer;
                          } else if (test) {
                              token.tests.push(test);
                          }
  
                          if (!selector.length || parser.name === COMBINATOR) {
                              tokens.push(token);
                              token = Selector._getToken(token);
                              if (parser.name === COMBINATOR) {
                                  token.combinator = Selector.combinators[match[1]];
                              }
                          }
                          found = true;
  
  
                      }
                  }
              } while (found && selector.length);
  
              if (!found || selector.length) { // not fully parsed
                  YAHOO.log('query: ' + query + ' contains unsupported token in: ' + selector, 'warn', 'Selector');
                  tokens = [];
              }
              return tokens;
          },
  
          _replaceShorthand: function(selector) {
              var shorthand = Selector.shorthand,
                  esc = selector.match(Selector._re.esc), // pull escaped colon, brackets, etc. 
                  attrs,
                  pseudos,
                  re, i, len;
  
              if (esc) {
                  selector = selector.replace(Selector._re.esc, '\uE000');
              }
  
              attrs = selector.match(Selector._re.attr);
              pseudos = selector.match(Selector._re.pseudos);
  
              if (attrs) {
                  selector = selector.replace(Selector._re.attr, '\uE001');
              }
  
              if (pseudos) {
                  selector = selector.replace(Selector._re.pseudos, '\uE002');
              }
  
  
              for (re in shorthand) {
                  if (shorthand.hasOwnProperty(re)) {
                      selector = selector.replace(new RegExp(re, 'gi'), shorthand[re]);
                  }
              }
  
              if (attrs) {
                  for (i = 0, len = attrs.length; i < len; ++i) {
                      selector = selector.replace(/\uE001/, attrs[i]);
                  }
              }
  
              if (pseudos) {
                  for (i = 0, len = pseudos.length; i < len; ++i) {
                      selector = selector.replace(/\uE002/, pseudos[i]);
                  }
              }
  
              selector = selector.replace(/\[/g, '\uE003');
              selector = selector.replace(/\]/g, '\uE004');
  
              selector = selector.replace(/\(/g, '\uE005');
              selector = selector.replace(/\)/g, '\uE006');
  
              if (esc) {
                  for (i = 0, len = esc.length; i < len; ++i) {
                      selector = selector.replace('\uE000', esc[i]);
                  }
              }
  
              return selector;
          },
  
          _attrFilters: {
              'class': 'className',
              'for': 'htmlFor'
          },
  
          getters: {
              href: function(node, attr) {
                  return Y_DOM.getAttribute(node, attr);
              }
          }
      };
  
  Y_mix(Selector, SelectorCSS2, true);
  Selector.getters.src = Selector.getters.rel = Selector.getters.href;
  
  // IE wants class with native queries
  if (Selector.useNative && Y_DOC.querySelector) {
      Selector.shorthand['\\.([^\\s\\\\(\\[:]*)'] = '[class~=$1]';
  }
  
  /**
   * The selector css3 module provides support for css3 selectors.
   * @module dom
   * @submodule selector-css3
   * @for Selector
   */
  
  /*
      an+b = get every _a_th node starting at the _b_th
      0n+b = no repeat ("0" and "n" may both be omitted (together) , e.g. "0n+1" or "1", not "0+1"), return only the _b_th element
      1n+b =  get every element starting from b ("1" may may be omitted, e.g. "1n+0" or "n+0" or "n")
      an+0 = get every _a_th element, "0" may be omitted 
  */
  
  Selector._reNth = /^(?:([\-]?\d*)(n){1}|(odd|even)$)*([\-+]?\d*)$/;
  
  Selector._getNth = function(node, expr, tag, reverse) {
      Selector._reNth.test(expr);
      var a = parseInt(RegExp.$1, 10), // include every _a_ elements (zero means no repeat, just first _a_)
          n = RegExp.$2, // "n"
          oddeven = RegExp.$3, // "odd" or "even"
          b = parseInt(RegExp.$4, 10) || 0, // start scan from element _b_
          result = [],
          siblings = Selector._children(node.parentNode, tag),
          op;
  
      if (oddeven) {
          a = 2; // always every other
          op = '+';
          n = 'n';
          b = (oddeven === 'odd') ? 1 : 0;
      } else if ( isNaN(a) ) {
          a = (n) ? 1 : 0; // start from the first or no repeat
      }
  
      if (a === 0) { // just the first
          if (reverse) {
              b = siblings.length - b + 1; 
          }
  
          if (siblings[b - 1] === node) {
              return true;
          } else {
              return false;
          }
  
      } else if (a < 0) {
          reverse = !!reverse;
          a = Math.abs(a);
      }
  
      if (!reverse) {
          for (var i = b - 1, len = siblings.length; i < len; i += a) {
              if ( i >= 0 && siblings[i] === node ) {
                  return true;
              }
          }
      } else {
          for (var i = siblings.length - b, len = siblings.length; i >= 0; i -= a) {
              if ( i < len && siblings[i] === node ) {
                  return true;
              }
          }
      }
      return false;
  };
  
  Y_mix(Selector.pseudos, {
      'root': function(node) {
          return node === node.ownerDocument.documentElement;
      },
  
      'nth-child': function(node, expr) {
          return Selector._getNth(node, expr);
      },
  
      'nth-last-child': function(node, expr) {
          return Selector._getNth(node, expr, null, true);
      },
  
      'nth-of-type': function(node, expr) {
          return Selector._getNth(node, expr, node.tagName);
      },
       
      'nth-last-of-type': function(node, expr) {
          return Selector._getNth(node, expr, node.tagName, true);
      },
       
      'last-child': function(node) {
          var children = Selector._children(node.parentNode);
          return children[children.length - 1] === node;
      },
  
      'first-of-type': function(node) {
          return Selector._children(node.parentNode, node.tagName)[0] === node;
      },
       
      'last-of-type': function(node) {
          var children = Selector._children(node.parentNode, node.tagName);
          return children[children.length - 1] === node;
      },
       
      'only-child': function(node) {
          var children = Selector._children(node.parentNode);
          return children.length === 1 && children[0] === node;
      },
  
      'only-of-type': function(node) {
          var children = Selector._children(node.parentNode, node.tagName);
          return children.length === 1 && children[0] === node;
      },
  
      'empty': function(node) {
          return node.childNodes.length === 0;
      },
  
      'not': function(node, expr) {
          return !Selector.test(node, expr);
      },
  
      'contains': function(node, expr) {
          var text = node.innerText || node.textContent || '';
          return text.indexOf(expr) > -1;
      },
  
      'checked': function(node) {
          return (node.checked === true || node.selected === true);
      },
  
      enabled: function(node) {
          return (node.disabled !== undefined && !node.disabled);
      },
  
      disabled: function(node) {
          return (node.disabled);
      }
  });
  
  Y_mix(Selector.operators, {
      '^=': '^{val}', // Match starts with value
      '!=': function(node, attr, val) { return node[attr] !== val; }, // Match starts with value
      '$=': '{val}$', // Match ends with value
      '*=': '{val}' // Match contains value as substring 
  });
  
  Selector.combinators['~'] = {
      axis: 'previousSibling'
  };
  YAHOO.register("selector", YAHOO.util.Selector, {version: "2.9.0", build: "2800"});
  
  }, '2.9.0' ,{"requires": ["yui2-yahoo", "yui2-dom"]});
  