var wlpopup211 = "http://www.webmasterlose.de/lose/clickbanner.php?id=4428&bid=17209&aid=21406&var1=&var2=&ref=";

  var shown = false;

  function leer() { }

  function opopup()
  {
    if (shown == true) { return; }
    shown = true;
    var win2 = window.open (wlpopup211,"wlpopup211",'');

    if (win2 == null)
    {
    }
  }

  opopup();