function WertHolen() {
  var Wert = "";
  if(document.cookie) {
   var Wertstart = document.cookie.indexOf("nav=") + 4;
   var Wertende = Wertstart + 5;
   if (Wertende == -1) Wertende = document.cookie.length;
   Wert = document.cookie.substring(Wertstart,Wertende);
  }
  return Wert;
 }

 function setCookie(n1) {
         document.cookie = "nav=" + n1;
     }
function setMenuitem() {
         if(document.cookie.indexOf("nav")!= -1){
         var lxnav = WertHolen(); }
         else {var lxnav = "nav02";}
          {document.getElementById(lxnav).style.display = "block";}
            if (lxnav != "nav01") {document.getElementById("nav01").style.display = "none";}
            if (lxnav != "nav02") {document.getElementById("nav02").style.display = "none";}
            if (lxnav != "nav04") {document.getElementById("nav04").style.display = "none";}
            if (lxnav != "nav06") {document.getElementById("nav06").style.display = "none";}
 }
 function showmenuitem(was){
         setCookie(was);
         name = document.cookie;

 if (document.getElementById(was).style.display == "none"){
  document.getElementById(was).style.display = "block";
  if (was != "nav01") {document.getElementById("nav01").style.display = "none"; }
  if (was != "nav02") {document.getElementById("nav02").style.display = "none"; }
  if (was != "nav04") {document.getElementById("nav04").style.display = "none"; }
  if (was != "nav06") {document.getElementById("nav06").style.display = "none";}
 }
}