title: Focus on bootstrap dropdown
body: <p>I am using a bootstrap dropdown, I want to focus on the dropdown so I can use keyboard to navigate over the list. What is the way to do it using jquery? 
  I tried to use $('#myULid').focus() and this is not working.</p>
  
  <p>I am able to open the dropdown, but not focus on it. </p>
  
  <pre><code>        &lt;button id="time_btn" type="button"
                  class="btn btn-reverse dropdown-toggle"
                  data-toggle="dropdown"&gt;
              &lt;/button&gt;
              &lt;ul class="dropdown-menu" role="menu"&gt;
                  &lt;li ng-repeat="item in items" &gt;&lt;a&gt;&lt;span&gt;test&lt;/span&gt;&lt;/a&gt;&lt;/li&gt;
          &lt;/ul&gt;
  </code></pre>