//  popup handling strict
//  Aufruf der Funktion per
//  <a href="html-or.jpg" onclick="return popup(this,123,456)" title="...">
var pop = null;
function popdown() {
  if (pop && !pop.closed) pop.close();
}
function popup(obj,w,h) {
  var url = (obj.getAttribute) ? obj.getAttribute('href') : obj.href;
  if (!url) return true;
  w = (w) ? w += 0 : 910;  // popup default size ( width )
  h = (h) ? h += 0 : 730;  // popup default size ( height )
  var args = 'width='+w+',height='+h+',resizable,scrollbars';
  popdown();
  pop = window.open(url,'',args);
  return (pop) ? false : true;
}
window.onunload = popdown;
window.onfocus = popdown;
//  popup handling strict
//  Loesung für: TARGET= neue Funktion erstellen ...
function ct(obj) {
    obj.target = '_blank';
}
// ... und Links auf diese Weise schreiben:
// <a href="http://meine.url.de" onclick="ct(this)">Linktext</a>