var browserName = navigator.appName;
	var browserVersion = parseInt(navigator.appVersion);
	var IE4 = ((browserName=="Microsoft Internet Explorer") && (browserVersion>=4));
	var NS4 = ((browserName=="Netscape") && (browserVersion>=4));
	var IE3 = ((browserName=="Microsoft Internet Explorer") && (browserVersion<4));
	var NS3 = ((browserName=="Netscape") && (browserVersion<4));	
	 
	if (NS4) {
		layerStyleRef = "layer.";
		layerRef = "document.layers";
		styleSwitch = "";}
	else if (IE4) {
		layerStyleRef = "layer.style";
		layerRef = "document.all";
		styleSwitch = ".style";};
function showLayer(layerName) {
	eval(layerRef+'["' + layerName+'"]' + styleSwitch + '.visibility = "visible"');};
function hideLayer(layerName) {
		eval(layerRef+'["' + layerName+'"]' + styleSwitch + '.visibility = "hidden"');};
function hideAll() {	
		hideLayer('menu1');
		hideLayer('menu2');
};