function fenster(){
xx=document.getElementById("body1").offsetWidth ;
fbr=xx/2;
if (fbr > 460 ) {fbr=450;}	
document.getElementById("Hintergrund").style.marginLeft=-fbr+"px";
xx=document.getElementById("body1").offsetHeight ;
fh=xx/2;
if (fh > 280 ) {fh=275;}	
document.getElementById("Hintergrund").style.marginTop=-fh+"px";
}
F1=""
function wopen(datei,breite,hoehe,sb)
{
if (F1.closed == false) F1.close();
F1 = window.open(datei,'F1','width=650, height=650, top=50, left=100, menubar=NO, toolbar=NO, scrollbars=YES, status=NO, resizable=NO');  
F1.focus(); 
}