/*
		 Initialize and render the MenuBar when its elements are ready 
		 to be scripted.
	*/

	YAHOO.util.Event.onContentReady("navigation", function () {

		var ua = YAHOO.env.ua,
			oAnim;  // Animation instance


		/*
			 "beforeshow" event handler for each submenu of the MenuBar
			 instance, used to setup certain style properties before
			 the menu is animated.
		*/

		function onSubmenuBeforeShow(p_sType, p_sArgs) {

			var oBody,
				oElement,
				oShadow,
				oUL;
		

			if (this.parent) {

				oElement = this.element;

				/*
					 Get a reference to the Menu's shadow element and 
					 set its "height" property to "0px" to syncronize 
					 it with the height of the Menu instance.
				*/

				oShadow = oElement.lastChild;
				oShadow.style.height = "0px";

				
				/*
					Stop the Animation instance if it is currently 
					animating a Menu.
				*/ 
			
				if (oAnim && oAnim.isAnimated()) {
				
					oAnim.stop();
					oAnim = null;
				
				}


				/*
					Set the body element's "overflow" property to 
					"hidden" to clip the display of its negatively 
					positioned <ul> element.
				*/ 

				oBody = this.body;


				//  Check if the menu is a submenu of a submenu.

				if (this.parent && 
					!(this.parent instanceof YAHOO.widget.MenuBarItem)) {
				

					/*
						There is a bug in gecko-based browsers and Opera where 
						an element whose "position" property is set to 
						"absolute" and "overflow" property is set to 
						"hidden" will not render at the correct width when
						its offsetParent's "position" property is also 
						set to "absolute."  It is possible to work around 
						this bug by specifying a value for the width 
						property in addition to overflow.
					*/

					if (ua.gecko || ua.opera) {
					
						oBody.style.width = oBody.clientWidth + "px";
					
					}
					
					
					/*
						Set a width on the submenu to prevent its 
						width from growing when the animation 
						is complete.
					*/
					
					if (ua.ie == 7) {

						oElement.style.width = oElement.clientWidth + "px";

					}
				
				}


				oBody.style.overflow = "hidden";


				/*
					Set the <ul> element's "marginTop" property 
					to a negative value so that the Menu's height
					collapses.
				*/ 

				oUL = oBody.getElementsByTagName("ul")[0];

				oUL.style.marginTop = ("-" + oUL.offsetHeight + "px");
			
			}

		}


		/*
			"tween" event handler for the Anim instance, used to 
			syncronize the size and position of the Menu instance's 
			shadow and iframe shim (if it exists) with its 
			changing height.
		*/

		function onTween(p_sType, p_aArgs, p_oShadow) {

			if (this.cfg.getProperty("iframe")) {
			
				this.syncIframe();
		
			}
		
			if (p_oShadow) {
		
				p_oShadow.style.height = this.element.offsetHeight + "px";
			
			}
		
		}


		/*
			"complete" event handler for the Anim instance, used to 
			remove style properties that were animated so that the 
			Menu instance can be displayed at its final height.
		*/

		function onAnimationComplete(p_sType, p_aArgs, p_oShadow) {

			var oBody = this.body,
				oUL = oBody.getElementsByTagName("ul")[0];

			if (p_oShadow) {
			
				p_oShadow.style.height = this.element.offsetHeight + "px";
			
			}


			oUL.style.marginTop = "";
			oBody.style.overflow = "";
			

			//  Check if the menu is a submenu of a submenu.

			if (this.parent && 
				!(this.parent instanceof YAHOO.widget.MenuBarItem)) {


				// Clear widths set by the "beforeshow" event handler

				if (ua.gecko || ua.opera) {
				
					oBody.style.width = "";
				
				}
				
				if (ua.ie == 7) {

					this.element.style.width = "";

				}
			
			}
			
		}


		/*
			 "show" event handler for each submenu of the MenuBar 
			 instance - used to kick off the animation of the 
			 <ul> element.
		*/

		function onSubmenuShow(p_sType, p_sArgs) {

			var oElement,
				oShadow,
				oUL;
		
			if (this.parent) {

				oElement = this.element;
				oShadow = oElement.lastChild;
				oUL = this.body.getElementsByTagName("ul")[0];
			

				/*
					 Animate the <ul> element's "marginTop" style 
					 property to a value of 0.
				*/

				oAnim = new YAHOO.util.Anim(oUL, 
					{ marginTop: { to: 0 } },
					.5, YAHOO.util.Easing.easeOut);


				oAnim.onStart.subscribe(function () {

					oShadow.style.height = "100%";
				
				});


				oAnim.animate();


				/*
					Subscribe to the Anim instance's "tween" event for 
					IE to syncronize the size and position of a 
					submenu's shadow and iframe shim (if it exists)  
					with its changing height.
				*/

				if (YAHOO.env.ua.ie) {
					
					oShadow.style.height = oElement.offsetHeight + "px";


					/*
						Subscribe to the Anim instance's "tween"
						event, passing a reference Menu's shadow 
						element and making the scope of the event 
						listener the Menu instance.
					*/

					oAnim.onTween.subscribe(onTween, oShadow, this);

				}


				/*
					Subscribe to the Anim instance's "complete" event,
					passing a reference Menu's shadow element and making 
					the scope of the event listener the Menu instance.
				*/

				oAnim.onComplete.subscribe(onAnimationComplete, oShadow, this);
			
			}
		
		}


		/*
			 Instantiate a MenuBar:  The first argument passed to the 
			 constructor is the id of the element in the page 
			 representing the MenuBar; the second is an object literal 
			 of configuration properties.
		*/

		var oMenuBar = new YAHOO.widget.MenuBar("navigation", { 
													autosubmenudisplay: true, 
													hidedelay: 750, 
													lazyload: true });


		/*
			 Subscribe to the "beforeShow" and "show" events for 
			 each submenu of the MenuBar instance.
		*/
		
		oMenuBar.subscribe("beforeShow", onSubmenuBeforeShow);
		oMenuBar.subscribe("show", onSubmenuShow);


		/*
			 Call the "render" method with no arguments since the 
			 markup for this MenuBar already exists in the page.
		*/

		oMenuBar.render();          
	
	});