/*! HTML5 Shiv v3 | @jon_neal @afarkas @rem | MIT/GPL2 Licensed */
(function (win, doc) {
	// feature detection: whether the browser supports unknown elements
	var supportsUnknownElements = (function (a) {
		a.innerHTML = '<x-element></x-element>';
		return a.childNodes.length === 1;
	})(doc.createElement('a'));

	// feature detection: whether the browser supports default html5 styles
	var supportsHtml5Styles = (function (nav, docEl, compStyle) {
		docEl.appendChild(nav);
		return (compStyle = (compStyle ? compStyle(nav) : nav.currentStyle).display) && docEl.removeChild(nav) && compStyle === 'block';
	})(doc.createElement('nav'), doc.documentElement, win.getComputedStyle);

	// html5 global so that more elements can be shived and also so that existing shiving can be detected on iframes
	// more elements can be added and shived with the following code: html5.elements.push('element-name'); shivDocument(document);
	var html5 = {
		// a list of html5 elements
		elements: 'abbr article aside audio bdi canvas data datalist details figcaption figure footer header hgroup mark meter nav output progress section summary time video'.split(' '),

		// the shiv function
		shivDocument: function (scopeDocument) {
			scopeDocument = scopeDocument || doc;

			// test if the document has already been shived
			if (scopeDocument.documentShived) {
				return;
			}
			scopeDocument.documentShived = true;

			// set local variables
			var
			documentCreateElement = scopeDocument.createElement,
			documentCreateDocumentFragment = scopeDocument.createDocumentFragment,
			documentHead = scopeDocument.getElementsByTagName('head')[0],
			documentCreateElementReplaceFunction = function (m) {
				documentCreateElement(m);
			};

			// shiv for unknown elements
			if (!supportsUnknownElements) {
				// shiv the document
				html5.elements.join(' ').replace(/\w+/g, documentCreateElementReplaceFunction);

				// shiv document create element function
				scopeDocument.createElement = function (nodeName) {
					var element = documentCreateElement(nodeName);
					if (element.canHaveChildren){
						html5.shivDocument(element.document);
					} 
					return element;
				};

				// shiv document create element function
				scopeDocument.createDocumentFragment = function () {
					return html5.shivDocument(documentCreateDocumentFragment());
				};
			}

			// shiv for default html5 styles
			if (!supportsHtml5Styles && documentHead) {
				var div = documentCreateElement('div');
				div.innerHTML = ['x<style>',
					'article,aside,details,figcaption,figure,footer,header,hgroup,nav,section{display:block;*zoom:1}', // Corrects block display not defined in IE6/7/8/9
					'audio{display:none}', // Corrects audio display not defined in IE6/7/8/9
					'canvas,video{display:inline-block;*display:inline;*zoom:1}', // Corrects canvas and video display not defined in IE6/7/8/9 (audio[controls] in IE7)
					'[hidden]{display:none}audio[controls]{display:inline-block;*display:inline;*zoom:1}', // Corrects 'hidden' attribute and audio[controls] display not present in IE7/8/9
					'mark{background:#FF0;color:#000}', // Addresses styling not present in IE6/7/8/9
				'</style>'].join('');
				documentHead.insertBefore(div.lastChild, documentHead.firstChild);
			}

			// return document (for potential chaining)
			return scopeDocument;
		}
	};

	// shiv the document
	html5.shivDocument(doc);

	win.html5 = html5;
})(this, document);