Show:
                            var NODE_TYPE = 'nodeType',
                                OWNER_DOCUMENT = 'ownerDocument',
                                DOCUMENT_ELEMENT = 'documentElement',
                                DEFAULT_VIEW = 'defaultView',
                                PARENT_WINDOW = 'parentWindow',
                                TAG_NAME = 'tagName',
                                PARENT_NODE = 'parentNode',
                                PREVIOUS_SIBLING = 'previousSibling',
                                NEXT_SIBLING = 'nextSibling',
                                CONTAINS = 'contains',
                                COMPARE_DOCUMENT_POSITION = 'compareDocumentPosition',
                                EMPTY_ARRAY = [],
                            
                                // IE < 8 throws on node.contains(textNode)
                                supportsContainsTextNode = (function() {
                                    var node = Y.config.doc.createElement('div'),
                                        textNode = node.appendChild(Y.config.doc.createTextNode('')),
                                        result = false;
                            
                                    try {
                                        result = node.contains(textNode);
                                    } catch(e) {}
                            
                                    return result;
                                })(),
                            
                            /**
                             * The DOM utility provides a cross-browser abtraction layer
                             * normalizing DOM tasks, and adds extra helper functionality
                             * for other common tasks.
                             * @module dom
                             * @main dom
                             * @submodule dom-base
                             * @for DOM
                             *
                             */
                            
                            /**
                             * Provides DOM helper methods.
                             * @class DOM
                             *
                             */
                            
                            Y_DOM = {
                                /**
                                 * Returns the HTMLElement with the given ID (Wrapper for document.getElementById).
                                 * @method byId
                                 * @param {String} id the id attribute
                                 * @param {Object} doc optional The document to search. Defaults to current document
                                 * @return {HTMLElement | null} The HTMLElement with the id, or null if none found.
                                 */
                                byId: function(id, doc) {
                                    // handle dupe IDs and IE name collision
                                    return Y_DOM.allById(id, doc)[0] || null;
                                },
                            
                                getId: function(node) {
                                    var id;
                                    // HTMLElement returned from FORM when INPUT name === "id"
                                    // IE < 8: HTMLCollection returned when INPUT id === "id"
                                    // via both getAttribute and form.id
                                    if (node.id && !node.id.tagName && !node.id.item) {
                                        id = node.id;
                                    } else if (node.attributes && node.attributes.id) {
                                        id = node.attributes.id.value;
                                    }
                            
                                    return id;
                                },
                            
                                setId: function(node, id) {
                                    if (node.setAttribute) {
                                        node.setAttribute('id', id);
                                    } else {
                                        node.id = id;
                                    }
                                },
                            
                                /*
                                 * Finds the ancestor of the element.
                                 * @method ancestor
                                 * @param {HTMLElement} element The html element.
                                 * @param {Function} fn optional An optional boolean test to apply.
                                 * The optional function is passed the current DOM node being tested as its only argument.
                                 * If no function is given, the parentNode is returned.
                                 * @param {Boolean} testSelf optional Whether or not to include the element in the scan
                                 * @return {HTMLElement | null} The matching DOM node or null if none found.
                                 */
                                ancestor: function(element, fn, testSelf, stopFn) {
                                    var ret = null;
                                    if (testSelf) {
                                        ret = (!fn || fn(element)) ? element : null;
                            
                                    }
                                    return ret || Y_DOM.elementByAxis(element, PARENT_NODE, fn, null, stopFn);
                                },
                            
                                /*
                                 * Finds the ancestors of the element.
                                 * @method ancestors
                                 * @param {HTMLElement} element The html element.
                                 * @param {Function} fn optional An optional boolean test to apply.
                                 * The optional function is passed the current DOM node being tested as its only argument.
                                 * If no function is given, all ancestors are returned.
                                 * @param {Boolean} testSelf optional Whether or not to include the element in the scan
                                 * @return {Array} An array containing all matching DOM nodes.
                                 */
                                ancestors: function(element, fn, testSelf, stopFn) {
                                    var ancestor = element,
                                        ret = [];
                            
                                    while ((ancestor = Y_DOM.ancestor(ancestor, fn, testSelf, stopFn))) {
                                        testSelf = false;
                                        if (ancestor) {
                                            ret.unshift(ancestor);
                            
                                            if (stopFn && stopFn(ancestor)) {
                                                return ret;
                                            }
                                        }
                                    }
                            
                                    return ret;
                                },
                            
                                /**
                                 * Searches the element by the given axis for the first matching element.
                                 * @method elementByAxis
                                 * @param {HTMLElement} element The html element.
                                 * @param {String} axis The axis to search (parentNode, nextSibling, previousSibling).
                                 * @param {Function} [fn] An optional boolean test to apply.
                                 * @param {Boolean} [all] Whether text nodes as well as element nodes should be returned, or
                                 * just element nodes will be returned(default)
                                 * The optional function is passed the current HTMLElement being tested as its only argument.
                                 * If no function is given, the first element is returned.
                                 * @return {HTMLElement | null} The matching element or null if none found.
                                 */
                                elementByAxis: function(element, axis, fn, all, stopAt) {
                                    while (element && (element = element[axis])) { // NOTE: assignment
                                            if ( (all || element[TAG_NAME]) && (!fn || fn(element)) ) {
                                                return element;
                                            }
                            
                                            if (stopAt && stopAt(element)) {
                                                return null;
                                            }
                                    }
                                    return null;
                                },
                            
                                /**
                                 * Determines whether or not one HTMLElement is or contains another HTMLElement.
                                 * @method contains
                                 * @param {HTMLElement} element The containing html element.
                                 * @param {HTMLElement} needle The html element that may be contained.
                                 * @return {Boolean} Whether or not the element is or contains the needle.
                                 */
                                contains: function(element, needle) {
                                    var ret = false;
                            
                                    if ( !needle || !element || !needle[NODE_TYPE] || !element[NODE_TYPE]) {
                                        ret = false;
                                    } else if (element[CONTAINS] &&
                                            // IE < 8 throws on node.contains(textNode) so fall back to brute.
                                            // Falling back for other nodeTypes as well.
                                            (needle[NODE_TYPE] === 1 || supportsContainsTextNode)) {
                                            ret = element[CONTAINS](needle);
                                    } else if (element[COMPARE_DOCUMENT_POSITION]) {
                                        // Match contains behavior (node.contains(node) === true).
                                        // Needed for Firefox < 4.
                                        if (element === needle || !!(element[COMPARE_DOCUMENT_POSITION](needle) & 16)) {
                                            ret = true;
                                        }
                                    } else {
                                        ret = Y_DOM._bruteContains(element, needle);
                                    }
                            
                                    return ret;
                                },
                            
                                /**
                                 * Determines whether or not the HTMLElement is part of the document.
                                 * @method inDoc
                                 * @param {HTMLElement} element The containing html element.
                                 * @param {HTMLElement} doc optional The document to check.
                                 * @return {Boolean} Whether or not the element is attached to the document.
                                 */
                                inDoc: function(element, doc) {
                                    var ret = false,
                                        rootNode;
                            
                                    if (element && element.nodeType) {
                                        (doc) || (doc = element[OWNER_DOCUMENT]);
                            
                                        rootNode = doc[DOCUMENT_ELEMENT];
                            
                                        // contains only works with HTML_ELEMENT
                                        if (rootNode && rootNode.contains && element.tagName) {
                                            ret = rootNode.contains(element);
                                        } else {
                                            ret = Y_DOM.contains(rootNode, element);
                                        }
                                    }
                            
                                    return ret;
                            
                                },
                            
                               allById: function(id, root) {
                                    root = root || Y.config.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_DOM._getDoc(root).getElementById(id)];
                                    }
                            
                                    return ret;
                               },
                            
                            
                                isWindow: function(obj) {
                                    return !!(obj && obj.scrollTo && obj.document);
                                },
                            
                                _removeChildNodes: function(node) {
                                    while (node.firstChild) {
                                        node.removeChild(node.firstChild);
                                    }
                                },
                            
                                siblings: function(node, fn) {
                                    var nodes = [],
                                        sibling = node;
                            
                                    while ((sibling = sibling[PREVIOUS_SIBLING])) {
                                        if (sibling[TAG_NAME] && (!fn || fn(sibling))) {
                                            nodes.unshift(sibling);
                                        }
                                    }
                            
                                    sibling = node;
                                    while ((sibling = sibling[NEXT_SIBLING])) {
                                        if (sibling[TAG_NAME] && (!fn || fn(sibling))) {
                                            nodes.push(sibling);
                                        }
                                    }
                            
                                    return nodes;
                                },
                            
                                /**
                                 * Brute force version of contains.
                                 * Used for browsers without contains support for non-HTMLElement Nodes (textNodes, etc).
                                 * @method _bruteContains
                                 * @private
                                 * @param {HTMLElement} element The containing html element.
                                 * @param {HTMLElement} needle The html element that may be contained.
                                 * @return {Boolean} Whether or not the element is or contains the needle.
                                 */
                                _bruteContains: function(element, needle) {
                                    while (needle) {
                                        if (element === needle) {
                                            return true;
                                        }
                                        needle = needle.parentNode;
                                    }
                                    return false;
                                },
                            
                            // TODO: move to Lang?
                                /**
                                 * Memoizes dynamic regular expressions to boost runtime performance.
                                 * @method _getRegExp
                                 * @private
                                 * @param {String} str The string to convert to a regular expression.
                                 * @param {String} flags optional An optinal string of flags.
                                 * @return {RegExp} An instance of RegExp
                                 */
                                _getRegExp: function(str, flags) {
                                    flags = flags || '';
                                    Y_DOM._regexCache = Y_DOM._regexCache || {};
                                    if (!Y_DOM._regexCache[str + flags]) {
                                        Y_DOM._regexCache[str + flags] = new RegExp(str, flags);
                                    }
                                    return Y_DOM._regexCache[str + flags];
                                },
                            
                            // TODO: make getDoc/Win true privates?
                                /**
                                 * returns the appropriate document.
                                 * @method _getDoc
                                 * @private
                                 * @param {HTMLElement} element optional Target element.
                                 * @return {Object} The document for the given element or the default document.
                                 */
                                _getDoc: function(element) {
                                    var doc = Y.config.doc;
                                    if (element) {
                                        doc = (element[NODE_TYPE] === 9) ? element : // element === document
                                            element[OWNER_DOCUMENT] || // element === DOM node
                                            element.document || // element === window
                                            Y.config.doc; // default
                                    }
                            
                                    return doc;
                                },
                            
                                /**
                                 * returns the appropriate window.
                                 * @method _getWin
                                 * @private
                                 * @param {HTMLElement} element optional Target element.
                                 * @return {Object} The window for the given element or the default window.
                                 */
                                _getWin: function(element) {
                                    var doc = Y_DOM._getDoc(element);
                                    return doc[DEFAULT_VIEW] || doc[PARENT_WINDOW] || Y.config.win;
                                },
                            
                                _batch: function(nodes, fn, arg1, arg2, arg3, etc) {
                                    fn = (typeof fn === 'string') ? Y_DOM[fn] : fn;
                                    var result,
                                        i = 0,
                                        node,
                                        ret;
                            
                                    if (fn && nodes) {
                                        while ((node = nodes[i++])) {
                                            result = result = fn.call(Y_DOM, node, arg1, arg2, arg3, etc);
                                            if (typeof result !== 'undefined') {
                                                (ret) || (ret = []);
                                                ret.push(result);
                                            }
                                        }
                                    }
                            
                                    return (typeof ret !== 'undefined') ? ret : nodes;
                                },
                            
                                generateID: function(el) {
                                    var id = el.id;
                            
                                    if (!id) {
                                        id = Y.stamp(el);
                                        el.id = id;
                                    }
                            
                                    return id;
                                }
                            };
                            
                            
                            Y.DOM = Y_DOM;