function bookmark(url, title) {
  var url = url || location.protocol + '//' + location.host;

  var title = title || location.host;

 if(document.all) {
    window.external.AddFavorite(url, title);
  }

  else if(window.sidebar) {
    window.sidebar.addPanel(title, url, '');
  }
  return false;
}