function fenster(seite, weite, hoehe, name)
{
var mon, toppos, leftpos, features;

toppos = (screen.height - hoehe)/2-30;
leftpos = (screen.width - weite)/2;
features = 'scrollbars=0,location=0,toolbar=0,menubar=0,resizable=0,status=0';
mon = window.open(seite,name,"width="+weite+",height="+hoehe+",top="+toppos+",left="+leftpos+", "+features);
mon.focus();
}