window.onload = rolloverInit;

function rolloverInit() {
var aImg=document.getElementById('TopNavWrap').getElementsByTagName('img');
var len=aImg.length;
for (var i=0; i<len; i++) {
    if (aImg[i].parentNode.nodeName == "A") {
        setupRollover(aImg[i]);
        }
    }
}

function setupRollover(thisImage) {
	thisImage.outImage = new Image();
	thisImage.outImage.src = thisImage.src;
	thisImage.onmouseout = rollOut;
	
	thisImage.overImage = new Image ();
	thisImage.overImage.src = "graphics/00000001/" + thisImage.id + "_on.png";
	thisImage.onmouseover = rollOver;
}

function rollOut() {
	this.src = this.outImage.src;
}

function rollOver () {
	this.src = this.overImage.src;
}