var openmenu="menu1";
if(document.layers)
   {window.captureEvents(Event.MOUSEDOWN);
    window.onmousedown=ausblenden;
   } else
   {document.onmouseup=ausblenden;
   }


function einblenden(param) 
{   openmenu=param;
    if (document.layers) 
    document.layers[openmenu].visibility ="show";		
    else 
    document.all[openmenu].style.visibility ="visible";
}

function ausblenden() 
{   if (document.layers) 
    document.layers[openmenu].visibility="hide";
    else 
    document.all[openmenu].style.visibility="hidden";
}