var popup;

function popWin (href) 
{
  if (popup == null || popup.closed) 
    {
      popup = window.open (href, "popup", "toolbar=no,location=no,directories=no,status=no,menubar=no,scrollbars=yes,resizable=yes,width=450,height=450")
    } 
  else 
    { 
      if (navigator.appName.substring(0.8) == "Netscape") 
        {
          popup.location.href = href;
          popup.focus();
        }
      else 
        {
          popup = window.open(href, "popup", "toolbar=no,location=no,directories=no,status=no,menubar=no,scrollbars=yes,resizable=yes,width=450,height=450")
        }
    }
  popup.focus();
}

function popUp (href) 
{
  top.defaultStatus= "Displaying popup";
  popWin (href);
}