var Fenster=null;
function popUp(meineSeite,meinName,w,h,scroll){
 LeftPosition = (screen.width) ? (screen.width-w)/2 : 0;
 TopPosition = (screen.height) ? (screen.height-h)/2 : 0;
 settings ='height='+h+',width='+w+',top='+TopPosition+',left='+LeftPosition+',scrollbars='+scroll+',resizable'
 Fenster = window.open(meineSeite,meinName,settings)
}