function popup(w,h,site) {
   x = screen.availWidth/2-w/2;
   y = screen.availHeight/2-h/2;
   popupWindow = window.open('http://www.hagnauer-hof.de/cms/js/pictureResized.php?path='+site,'','width='+w+',height='+h+',left='+x+',top='+y+',screenX='+x+',screenY='+y);
}