function bookmark(sitename)
{
  ns="Netscape users, use CTRL+D to bookmark this site."
  if ((navigator.appName=='Microsoft Internet Explorer') &&
    (parseInt(navigator.appVersion)>=4))
  {
    window.external.AddFavorite(window.location.href, sitename);
  }
  else if (window.sidebar) { // Mozilla Firefox Bookmark
        window.sidebar.addPanel(sitename, window.location.href,"");
  }
  else if (navigator.appName=='Netscape')
  {
    alert(ns);
  }

}