var displayedImage = "";

function ImageRollOver( ev )
{	
	var srcElement;	
	if ( ev )
	{
		if ( ev.target )
		{
			srcElement = ev.target;
		}
		else
		{		
			srcElement = ev.srcElement;
		}
	}
	else
	{
		srcElement = window.event.srcElement;
	}
	
	var imgElement = srcElement;
	
	if ( srcElement.tagName == "DIV" )
	{
		if ( srcElement.getAttribute( "thumb" ) )
		{
			var imageCol = srcElement.getElementsByTagName( "IMG" );
			imgElement = imageCol[0];
		}
		else
		{
			return;
		}
	}
	
	if ( imgElement.className == "thumb" )
	{
		
		if ( displayedImage != imgElement.getAttribute( "id" ) )
		{
			displayedImage = imgElement.getAttribute( "id" );

			var mainImageEl = document.getElementById("mainimage")
			var aEl = mainImageEl.parentNode;

			var oldSrc = mainImageEl.src;
			var newSrc = preLoad[displayedImage];
			mainImageEl.src = newSrc;

	                if (aEl.getAttribute("href")) {
			  var aHref = aEl.getAttribute("href");
                          var ar = aHref.match(/([^# ]+)show=([\w.]+)(;[\w.]*|$)/);
			  var newHref = RegExp.$1 + "show=" + displayedImage + RegExp.$3;
	                  aEl.setAttribute("href", newHref);
		        }
		}
	}
		
	return srcElement;
}

if ( document.attachEvent )
{
	document.attachEvent( "onmousemove", ImageRollOver );
}
else
{
	document.onmousemove = ImageRollOver;
}