var untermenue=new Array("um1","um2","um3","um4","um5");

function show(ebene1)
{
if(document.getElementById)
{
clearout();cover();
document.getElementById(ebene1).style.visibility="visible";
}}
	
function cover() 
{
for (i=0;i<untermenue.length;i++)
{
document.getElementById(untermenue[i]).style.visibility="hidden";
}}
	
function out()
{
timer=setTimeout("cover()",500);
}
	
function clearout() 
{
if(window.timer)
{
clearTimeout(timer);
}}