function oeffnefenster (url) {
 fenster = window.open(url, "fenster1", "height=520,width=540,top=200,left=200,status=yes,scrollbars=no,resizable=no");
 fenster.focus();
}

function nothing(){}
function tab(i) { 
if (document.getElementById){
		if (document.getElementById(i).style.display=="none")
             (document.getElementById(i).style.display="") ;
       else (document.getElementById(i).style.display="none")  ; }
else if (document.all) {
		if (document.all[i].style.display=="none")
           (document.all[i].style.display="") ;
        else (document.all[i].style.display="none")  ; }
else if (document.layers) {
		if (document[i].style.display=="none")
           (document[i].style.display="") ;
        else (document[i].style.display="none")  ; }
}