var winn="";
var ok=false;
function FensterZeigen(layn) {
   if ((winn!="") && (winn!=layn)) {
      FensterAus(winn);
   }
    var myObj = document.getElementById(layn);
	if(document.layers) {
	    	if ((winn!=layn) || (ok==false)) {
			document.layers[layn].visibility='show';
			ok=true;
			winn=layn;
		}	
	}
	else
	{
	 	if ((winn!=layn) || (ok==false)) {
			myObj.style.visibility = "visible";
			ok=true;
			winn=layn;
		}	
	}	
}

function FensterAus(layn){
    var myObj = document.getElementById(layn);
	if(document.layers){
		document.layers[layn].visibility='hide';
		ok=false;
		winn="";
	}
	else
	{
        myObj.style.visibility = "hidden";
		ok=false;
		winn="";
	}	
}
function FensterAusAll() {
    if (winn!="") {
       var myObj = document.getElementById(winn);
	   if(document.layers){
		   document.layers[winn].visibility='hide';
		   ok=false;
	       winn="";
	   }
    	else
	   {
          myObj.style.visibility = "hidden";
		  ok=false;
		  winn="";
       }
	}   	
}