function openZeWindow() {
  window.open(this.href, this.title, "width=200,height=300,resizable=1 , scrollbars=yes" );
  return false;
}

window.onload = function() {
 
  MM_preloadImages('img/acces-over.gif');

  var aArray = document.getElementsByTagName('a');
 
  for(var i = 0; i < aArray.length; i++) {
 
    if(aArray[i].className == "popup" ) {
      aArray[i].onclick = openZeWindow;
    }
  }
}