javascript:

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.jpg";
	thisImage.onmouseover = rollOver;	
}

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

}

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


function showPic (whichpic) {
	if (document.getElementById) {
	document.getElementById ('placeholder') .src = whichpic.href;

	return false;
	} 	
	else {
	return true;
	}
}