function popup(url,wdth,hght,scrll,nm) {
	var winl = (screen.width - wdth) / 2;
	var wint = (screen.height - hght) / 2;
	hauptfenster = window.open(url,nm,'top='+wint+',left='+winl+',toolbar=no,location=no,directories=no,status=no,menubar=no,scrollbars='+scrll+',resizable=no,copyhistory=no,width='+wdth+',height='+hght);
	hauptfenster.focus();
}