function showTour(){
  var tb= document.createElement("div");
  tb.id="tourback";
  var tbinner= document.createElement("div");
      tbinner.id="tbi";
  var body=document.getElementsByTagName("body")[0];
      body.appendChild(tb); 
      body.appendChild(tbinner);

  var tbp= document.createElement("p");
  var tbf= document.createElement("iframe");
  var ref=document.getElementById("tour");
  var path= ref.search.match(/\w+\//g);
      tbf.src="/"+path.join("")+"besichtigung.htm";
      tbinner.appendChild(tbp);
      tbinner.appendChild(tbf);
  var tba= document.createElement("a");
      tbp.appendChild(tba);
  var atext= document.createTextNode("X");
      tba.appendChild(atext);
      tba.href="javascript:void(0);"
      tba.onclick=function(){
         document.getElementById('tourback').style.display='none';
         document.getElementById('tbi').style.display='none';
         };
  ref.href="javascript:void(0);";
  ref.onclick=function(){
    document.getElementById("tourback").style.display="inline";
    document.getElementById("tbi").style.display="inline";
    };
  }
  commands.unshift("showTour();");