function addToFavorites() {
  var site_host = 'http://<?= $HTTP_HOST ?>';
  var site_title = '<?= $title ?>';

  var ms = navigator.appVersion.indexOf("MSIE");
  var ie5 = (ms > 0) && (parseInt(navigator.appVersion.substring(ms + 5, ms + 7)) >= 5);

  if (ie5)
    window.external.AddFavorite(site_host, site_title);
  else
    window.alert("<?= $lang['_sites_error_browserdoesntsupporthomepage'] ?>");
}