function preload(imgObj,imgSrc) 
{
	if (document.images) 
	{
		eval(imgObj+' = new Image()');
		eval(imgObj+'.src = "'+imgSrc+'"');
	}
}

function changeImage(layer,imgName,imgObj) 
{
	if (document.images) 
	{
		if (document.layers && layer!=null) 
		{ 
				eval('document.layers["'+layer+'"].document.images["'+imgName+'"].src = '+imgObj+'.src');
				
			}
			else 
			{
				document.images[imgName].src = eval(imgObj+".src");
			}
	}
}