function ml(url) {
  var width = 470;
  var height = 230;
  var left = (screen.width - width)/2;
  var top = (screen.height - height)/2;
  var params = 'width='+width+', height='+height;
  params += ', top='+top+', left='+left;
  params += ', directories=no';
  params += ', location=no';
  params += ', menubar=no';
  params += ', resizable=no';
  params += ', scrollbars=no';
  params += ', status=no';
  params += ', toolbar=no';
  newwin=window.open(url,'MailingList', params);
  if (window.focus) {
    newwin.focus();
  }
  return false;
}
/*
Usage: <a href="javascript: void(0)" onclick="ml('mypage.html');">my popup</a>
*/