function auf(menue)
   {
   var isNS4 = (document.layers ? true : false);
   if(document.all){
       document.all[menue].style.visibility="visible";
   }
   if(isNS4){
      document.layers[menue].visibility="show";
   }
}

function zu(menue)
   {
   var isNS4 = (document.layers ? true : false);
   if(document.all){
       document.all[menue].style.visibility="hidden";
   }
   if(isNS4){
      document.layers[menue].visibility="hide";
   }
}