title: window sidebar addPanel not work in firefox
body: <pre><code>&lt;script&gt;
      function Bookmark() {
  
          alert(navigator.userAgent);
          if (window.sidebar) { // Mozilla Firefox Bookmark
              window.sidebar.addPanel(location.href, document.title, "");
          }
          else if (window.external) { // IE Favorite
              window.external.AddFavorite(location.href, document.title);
          }
          else if (window.opera &amp;&amp; window.print) {
              alert("ASAS");
              var e = document.createElement('a');
              e.setAttribute('href', location.href);
              e.setAttribute('title', document.title);
              e.setAttribute('rel', 'sidebar');
              e.click();
          }
      }
  &lt;/script&gt;
  
  &lt;a href="#" onclick="Bookmark()"&gt;Bookmark&lt;/a&gt;
  </code></pre>
  
  <p>I has a script to let user click to bookmark the page.  It work ok in IE, but it not work in Firefox24.0 version.  It show me error window.sidebar.addPanel is not a function.  Any one has idea whats go wrong for the above code.  Please help!!!  Brilliant thanks.</p>