window.onload=rolloverInit;
function rolloverInit() {
	for (var i=0; i<document.images.length; i++) {
		if (document.images[i].parentNode.tagName =="A") {
		setupRollover(document.images[i]);
		}}
		}
function setupRollover(thisImage) {
	thisImage.outImage = new Image();
	thisImage.outImage.src = thisImage.src;
	thisImage.onmouseout = rollOut;
	
	thisImage.overImage = new Image();
	thisImage.overImage.src = "images/"+thisImage.id + "_on.gif";
	thisImage.onmouseover = rollOver;
	}
	function rollOver() {
		this.src = this.overImage.src;
		}
		
	function rollOut() {
		this.src = this.outImage.src;
		}