var bIE = document.all ? true : false;  
var bSafari = navigator.userAgent.toLowerCase().indexOf("safari") != -1;
var aNavOverImages = new Array("aboutus", "programs", "sponsors", "affiliates", "events", "pictures", "contact", "login");
var sCurrentRO = "base";
var sSection; //set in body on sub pages

var nInterval;
var nOpacity; 
var sCurrentFade;

//add code nav initialize code to onload event
if (document.getElementById) {
	addEvent(window, "onload", navInit);
	preloadImages();
}

/*********************************************
 * preload navigation off images used in rollover
 *********************************************/	  
function preloadImages() 
{  
	var iImage = new Image();
	for (var i=0; i < aNavOverImages.length; i++) {
		iImage.src = "nav_" + aNavOverImages[i] + "_on.gif";
	}  
}

/*********************************************
 * initialize the navigation
 *********************************************/	
function navInit() 
{	
	if (document.getElementById)
	{

		//start mouse tracking for carat movement
		if (! bIE) 
		{
			document.captureEvents(Event.MOUSEMOVE);
		}
		
		document.onmousemove = getMouseXY;	

		//add rollover functionality to each nav button

		for (var i=0; i < aNavOverImages.length; i++) 
		{
			var oLink = document.getElementById(aNavOverImages[i]);
				oLink.onmouseover = function() {			
			var sID = this.id.substring(0, this.id.length);
				clearInterval(nInterval);			
			
				hideRO();

				if (sCurrentRO != sID) 
				{				
					
				//update nav states
					this.firstChild.src = "nav_" + sID + "_on.gif";			
						if (sCurrentRO != "base")
						{
							document.getElementById(sCurrentRO).firstChild.src = "nav_" + sCurrentRO + "_off.gif";	
						}
		
							document.getElementById("ro_base").style.display = "none";				
							document.getElementById("ro_" + sCurrentRO).style.display = "none";										
						
						if (document.getElementById("ro_" + sID).style.display != "block")
							{
								document.getElementById("ro_" + sID).style.display = "block";
								document.getElementById("roContentHit").style.display = "block";	

							//fade for modern browsers except safari
							if (! bSafari)
								{				
									sCurrentFade = sID;
									roImg = document.getElementById("ro_" + sCurrentFade + "_img").style;
									nOpacity = 0;
									roImg.filter = "alpha(opacity=0)"; 
									roImg.KhtmlOpacity = nOpacity;            
									roImg.MozOpacity = nOpacity;              
									roImg.opacity = nOpacity;							
								
									nInterval = setInterval(fadeUpRO, 60);								
								}
							}

						document.getElementById("ro_" + sID).onmouseover = hideRO;	
						document.getElementById("roContentHit").onmouseover = hideRO;
	
						sCurrentRO = sID;				
					}
			}
		}  	

		//mouseout functionality to surrounding areas
		document.getElementById('header_shim_left').onmouseover = hideRO;
		document.getElementById('HeaderLogo').onmouseover = hideRO;
		document.getElementById('HeaderPicture').onmouseover = hideRO;
		//document.getElementById('Imagery').onmouseover = hideRO;

	}	
}


/*********************************************
 * set the opacity of the rollover image
 *********************************************/	
function setOpacity()
{
	var oImg = document.getElementById("ro_" + sCurrentFade + "_img").style;
 	oImg.filter = "alpha(opacity=" + nOpacity + ")"; 
	oImg.KhtmlOpacity = (nOpacity / 100);            
	oImg.MozOpacity = (nOpacity / 100);              
	oImg.opacity = (nOpacity / 100);
	
	//workaround to prevent mozilla opacity stutter on reaching 100%	
	if (! document.all)
	{
		document.fDebug.elements[0].value = (nOpacity / 100);
	}	
}

/*********************************************
 * control fade up the rollover image
 *********************************************/	
function fadeUpRO()
{
	if (nOpacity < 100)
	{
		nOpacity += 10;
		setOpacity();
	}
	else 
	{
		clearInterval(nInterval);
	}
}

/*********************************************
 * hide the currently displayed nav rollover item
 *********************************************/	
function hideRO()
{
	if (sCurrentRO != "base")
	{
		document.getElementById("ro_" + sCurrentRO).style.display = "none";		
		document.getElementById(sCurrentRO).firstChild.src = "nav_" + sCurrentRO + "_off.gif";		
		document.getElementById("roContentHit").style.display = "none";
		document.getElementById("ro_base").style.display = "block";	
//		document.getElementById("ContentCell").style.backgroundImage = "url(images/shared/back_content.jpg)";																										
//		document.getElementById("ContentCell").style.backgroundImage = "KOBHeader.gif)";																										
		document.getElementById("ContentCell").style.backgroundColor = "transparent";	
		sCurrentRO = "base";
	}
}
 

/*********************************************
 * get mouse coordiates
 *********************************************/	
function getMouseXY(e)
{
	var nX, nY;
//nYTop sets how far down from the top the area begins
	var nYTop = 171;
//nYBottom sets how far from the top before the area ends
	var nYBottom = 230;
//nYLeft Controls how far from the left the area begins
	var nYLeft = 27;
//nYRight Contols how far to the right before the area ends
	var nYRight = 543;
	
	if (bIE)
	{
		nX = event.clientX + document.body.scrollLeft;
		nY = event.clientY + document.body.scrollTop;
	}
	else
	{
		nX = e.pageX;
		nY = e.pageY;
	}
	
	//offset y position if page scrolled
	var nScrollOffset;
	if (document.documentElement.scrollTop)
	{		
		nScrollOffset = document.documentElement.scrollTop;
		if ((nScrollOffset) && (nScrollOffset > 0))
		{		
			if (document.all) 
			{
				nY = nScrollOffset + nY;
			} 
			else 
			{
				nYTop -= nScrollOffset;
				nYBottom -= nScrollOffset;				
				nY -= nScrollOffset;
			}
		}
	}
	
	//move carat to match position, within range	
	if ((nY >= nYTop) && (nY <= nYBottom)) 
	{
		if ((nX >= nYLeft) && (nX <= nYRight))
		{
			document.getElementById('Carat').style.visibility = "visible";
			document.getElementById('Carat').style.left = (nX - 7) + "px";	
		} 
		else 
		{
			document.getElementById('Carat').style.visibility = "hidden";
		}
	} 
	else 
	{
			document.getElementById('Carat').style.visibility = "hidden";
	}
	return true;
}	

/*********************************************
 * bind an event and method
 *********************************************/	
function addEvent(oTarget, sType, fpDest) 
{
	var oOldEvent = oTarget[sType];
	if (typeof oOldEvent != "function") 
	{
		oTarget[sType] = fpDest;
	}
	else
	{
		oTarget[sType] = function(e)
		{
			oOldEvent(e);
			fpDest(e);
		}
	}
}