function swapImage(layerName, imgName, imgObj) { //layerName...null for no layer
	if ((document.layers) && (layerName != null)) {
		eval('document.'+layerName+'.document.images["'+imgName+'"].src = '+imgObj+'.src');
	} else {
		document.images[imgName].src = eval(imgObj+".src");
	}
}