function SimpleSwap(el,which){
		  el.src=el.getAttribute(which || "origsrc");
		}
		
		function SimpleSwapSetup(){
		  var x = document.getElementsByTagName("img");
		  for (var i=0;i<x.length;i++){
			var oversrc = x[i].getAttribute("oversrc");
			if (!oversrc) continue;
			  
			// preload image
			// comment the next two lines to disable image pre-loading
			x[i].oversrc_img = new Image();
			x[i].oversrc_img.src=oversrc;
			// set event handlers
			x[i].onmouseover = new Function("SimpleSwap(this,'oversrc');");
			x[i].onmouseout = new Function("SimpleSwap(this);");
			// save original src
			x[i].setAttribute("origsrc",x[i].src);
		  }
		}
		
		var PreSimpleSwapOnload =(window.onload)? window.onload : function(){};
		window.onload = function(){PreSimpleSwapOnload(); SimpleSwapSetup();}