function openWindow(url, naam, features) 
  {
    if (typeof _hwin == "object" && _hwin && !_hwin.closed) 
      {
	_hwin.location.replace(url)
      } 
    else 
      {
	_hwin = window.open(url, naam, features);
      }
    setTimeout("_hwin.focus()", 255);
}