<!--
newwindow=false;
function oeffnefenster (url) {
  if(newwindow&&newwindow.closed==false)
    newwindow.close()
    var l = (screen.availWidth - 600) / 2;
    var t = (screen.availHeight - 400) / 2;
    newwindow = window.open(url,"newwindow","width=" + 600 +
                                            ",height=" + 400 +
                                            ",left=" + l +
                                            ",top=" + t + ";");
  newwindow.focus();
}
//-->