title: event.keyCode == 13 not working in Firefox
body: <p>I have a function to send comments on <code>enter</code> (and not send on <code>shift+enter</code>):</p>
  
  <pre><code>$(msg).keypress(function (e) {
      if (event.keyCode == 13 &amp;&amp; event.shiftKey) {
          event.stopPropagation();
      } else if (e.which == 13) {
          // ...
      }
  });
  </code></pre>
  
  <p>It is working on Chrome but not in Firefox.</p>