var prevImageID = new Array();
var prevImageSource = new Array();
var prevMenuID="";
var prevHighlight =0;
var TimeOutValue = 60000;
var imageSourceFiles;
var baseRef = "";



imageSourceFiles = new Array();

// declare all of the source files
imageSourceFiles["unsw_singapore_but"] = new Array();
imageSourceFiles["unsw_singapore_but"]["Over"] = baseRef + "_images/unsw_singapore_but_over.gif";
imageSourceFiles["unsw_singapore_but"]["Highlight"] = baseRef + "_images/unsw_singapore_but_hl.gif";
imageSourceFiles["unsw_singapore_but"]["Default"] = baseRef + "_images/unsw_singapore_but.gif";

imageSourceFiles["unsw_but"] = new Array();
imageSourceFiles["unsw_but"]["Over"] = baseRef + "_images/unsw_but_over.gif";
imageSourceFiles["unsw_but"]["Highlight"] = baseRef + "_images/unsw_but_hl.gif";
imageSourceFiles["unsw_but"]["Default"] = baseRef + "_images/unsw_but.gif";

imageSourceFiles["unsw_asia_but"] = new Array();
imageSourceFiles["unsw_asia_but"]["Over"] = baseRef + "_images/unsw_asia_but_over.gif";
imageSourceFiles["unsw_asia_but"]["Highlight"] = baseRef + "_images/unsw_asia_but_hl.gif";
imageSourceFiles["unsw_asia_but"]["Default"] = baseRef + "_images/unsw_asia_but.gif";

imageSourceFiles["alumni_events_but"] = new Array();
imageSourceFiles["alumni_events_but"]["Over"] = baseRef + "_images/alumni_events_but_over.gif";
imageSourceFiles["alumni_events_but"]["Highlight"] = baseRef + "_images/alumni_events_but_hl.gif";
imageSourceFiles["alumni_events_but"]["Default"] = baseRef + "_images/alumni_events_but.gif";

imageSourceFiles["links_but"] = new Array();
imageSourceFiles["links_but"]["Over"] = baseRef + "_images/links_but_over.gif";
imageSourceFiles["links_but"]["Highlight"] = baseRef + "_images/links_but_hl.gif";
imageSourceFiles["links_but"]["Default"] = baseRef + "_images/links_but.gif";

imageSourceFiles["unsw_singapore_menu_1_but"] = new Array();
imageSourceFiles["unsw_singapore_menu_1_but"]["Over"] = baseRef + "_images/menu_location_b.gif";
imageSourceFiles["unsw_singapore_menu_1_but"]["Highlight"] = baseRef + "_images/menu_location_b.gif";
imageSourceFiles["unsw_singapore_menu_1_but"]["Default"] = baseRef + "_images/menu_location_w.gif";

imageSourceFiles["unsw_singapore_menu_2_but"] = new Array();
imageSourceFiles["unsw_singapore_menu_2_but"]["Over"] = baseRef + "_images/menu_staff_b.gif";
imageSourceFiles["unsw_singapore_menu_2_but"]["Highlight"] = baseRef + "_images/menu_staff_b.gif";
imageSourceFiles["unsw_singapore_menu_2_but"]["Default"] = baseRef + "_images/menu_staff_w.gif";

imageSourceFiles["unsw_singapore_menu_3_but"] = new Array();
imageSourceFiles["unsw_singapore_menu_3_but"]["Over"] = baseRef + "_images/menu_activities_b.gif";
imageSourceFiles["unsw_singapore_menu_3_but"]["Highlight"] = baseRef + "_images/menu_activities_b.gif";
imageSourceFiles["unsw_singapore_menu_3_but"]["Default"] = baseRef + "_images/menu_activities_w.gif";

imageSourceFiles["unsw_singapore_menu_4_but"] = new Array();
imageSourceFiles["unsw_singapore_menu_4_but"]["Over"] = baseRef + "_images/menu_events_b.gif";
imageSourceFiles["unsw_singapore_menu_4_but"]["Highlight"] = baseRef + "_images/menu_events_b.gif";
imageSourceFiles["unsw_singapore_menu_4_but"]["Default"] = baseRef + "_images/menu_events_w.gif";

imageSourceFiles["menu_unsw_links_but"] = new Array();
imageSourceFiles["menu_unsw_links_but"]["Over"] = baseRef + "_images/menu_unsw_links_b.gif";
imageSourceFiles["menu_unsw_links_but"]["Highlight"] = baseRef + "_images/menu_unsw_links_b.gif";
imageSourceFiles["menu_unsw_links_but"]["Default"] = baseRef + "_images/menu_unsw_links_w.gif";
imageSourceFiles["unsw_links2_but"] = imageSourceFiles["menu_unsw_links_but"];

imageSourceFiles["menu_other_contacts_but"] = new Array();
imageSourceFiles["menu_other_contacts_but"]["Over"] = baseRef + "_images/menu_other_contacts_b.gif";
imageSourceFiles["menu_other_contacts_but"]["Highlight"] = baseRef + "_images/menu_other_contacts_b.gif";
imageSourceFiles["menu_other_contacts_but"]["Default"] = baseRef + "_images/menu_other_contacts_w.gif";
imageSourceFiles["other_links2_but"] = imageSourceFiles["menu_other_contacts_but"];

function processClicks() {
	cancelMenus();
	resetImages(1);
}

if (window.Event) // Navigator 4.0x
	document.captureEvents(Event.MOUSEUP);

document.onmouseup = processClicks;

/* Retrive the image object by looping whie comparing to the object name*/
function findDOMObject(nameOfObject) {
	for (var i = 0; i < document.images.length; i++) {
		if (document.images[i].name==nameOfObject) return document.images[i];
	}
	
	if(document.getElementById)
		return document.getElementById(nameOfObject);
	
}




function rollOverImage(imageID, isHighlight, myLevel)
{
	if(myLevel == 1)
		cancelMenus(imageID);
	
	var prevImageHref;
	var prevImage = prevImageID[myLevel];
	var theImage = imageID + "_but";
	
	if (prevImage && prevImageSource[prevImage])
		prevImageHref = prevImageSource[prevImage];
	else if(prevImage)
		prevImageHref = imageSourceFiles[prevImage]["Default"];
		
	//IE5 and Netscape 6
	if(document.getElementById)
	{ 
		if(prevImage)
		{
			if(prevImage)
			{
				
				(findDOMObject(prevImage)).src= prevImageHref;
			}
		}

		prevImageSource[theImage] = (findDOMObject(theImage)).src;
		(findDOMObject(theImage)).src = imageSourceFiles[theImage]["Over"];
	}
	
	//Netscape 4
	else if(document.images)
	{

		if(prevImage != "")
		{
			document.images[prevImageID].src = prevImageHref;
		}
		prevImageSource[theImage] = document.images[theImage].src;
		document.images[theImage].src = imageSourceFiles[theImage]["Over"];;
	}	
	
	prevImageID[myLevel] = theImage;
	prevHighlight = isHighlight;
}



function resetImages(myLevel)
{
	var prevImageHref;
	if(myLevel > 0){
		prevImage = prevImageID[myLevel];
		if (prevImage && prevImageSource[prevImage])
			prevImageHref = prevImageSource[prevImage];
		else if(prevImage)
			prevImageHref = imageSourceFiles[prevImage]["Default"];
		
		
		if(document.getElementById)
		{	
			if(prevImageHref && prevImage )
			
				(findDOMObject(prevImage)).src = prevImageHref;
		}
		else if(document.images)
		{	
			if(prevImage)
			{
				document.images[prevImage] .src = prevImageHref;
			}
		}
		
		return false;
	}

}

function showMenu(menuID,isHighlight)
{
	theMenu = menuID + "_menu";
	theImage = menuID + "_but";
	
	rollOverImage(menuID,isHighlight,1);
	
	//IE5 and Netscape 6
	if(document.getElementById)
	{
		if (document.getElementById(prevMenuID)){
			(findDOMObject(prevMenuID)).style.visibility = 'hidden';
		}
		if (document.getElementById(theMenu)){
			(document.getElementById(theMenu)).style.visibility = 'visible';
		}
	}
	//Netscape 4
	else if(document.layers)
	{
		if(document.layers[prevMenuID])
			document.layers[prevMenuID].visibility = 'hide';
		if(document.layers[theMenu])
			document.layers[theMenu].visibility = 'visible';
		
	}
	
	prevMenuID = theMenu;
}

function cancelMenus(menuID)
{
	theMenu = menuID + "_menu";
	theImage = menuID + "_but";
	
	/* IE and Netscape6*/
	if(document.getElementById)
	{
		if(prevMenuID)
		{
			if(prevMenuID!=menuID && document.getElementById(prevMenuID))
				(document.getElementById(prevMenuID)).style.visibility = "hidden";

		}
	}
	else if(document.layers)
	{
		if(prevHighlight>0)
		{
			if(prevLayer!="" && document.layers["Menu"+prevLayer])
				document.layers["Menu"+prevLayer].visibility	= "hide";

			document.images["ImgMenu"+prevImage].src = "/images/ROhMenu"+prevImage+".gif";
		}
	}
}