DOM = (document.getElementById) ? 1 : 0;
NS4 = (document.layers) ? 1 : 0;


<!-- PRINTING JAVASCRIPT FOR MENUCLASS III -->
var index = 0;
var imgobj = new Array();
function preloadSwitchImg(path, name) {
    imgobj[index] = new Array(3);
    imgobj[index][0] = new Image();
    imgobj[index][0].src = path + "_off.jpg";
    imgobj[index][1] = new Image();
    imgobj[index][1].src = path + "_on.jpg";
    imgobj[index][2] = "img_" + name;
    index++;
}
function switchImg(name, on) {
	if (NS4){
		// Fix for Netscape 4 div bug - find image in document.layers object instead (will NOT work for nested divs)
		for (a = 0; a < document.layers.length; a++) {
			if (document.layers[a].document.images[name]) {
				for (i = 0; i < index; i++) {
					if (name == imgobj[i][2]) document.layers[a].document.images[imgobj[i][2]].src = (on) ? imgobj[i][1].src : imgobj[i][0].src;
				}
			return true;
			}
		}
	} else {
		for (i = 0; i < index; i++) {
			if (name == imgobj[i][2]) document.images[imgobj[i][2]].src = (on) ? imgobj[i][1].src : imgobj[i][0].src;
		}
	}
}
<!-- DONE PRINTING JAVASCRIPT FOR MENUCLASS III -->