title: Add class to parent element
body: <p>I know this has been asked many times before, but I could not find anything that worked. 
  I will need to add a class to a div that gets autogenerated over my ul. </p>
  
  <p>This is my html code:</p>
  
  <pre><code>&lt;div class="wrapper"&gt;
      &lt;ul id="bx-pager"&gt;
         &lt;li&gt;&lt;a&gt;&lt;img&gt;&lt;/a&gt;&lt;/li&gt;
         &lt;li&gt;&lt;a&gt;&lt;img&gt;&lt;/a&gt;&lt;/li&gt;
      &lt;/ul&gt;
  &lt;/div&gt;
  </code></pre>
  
  <p>I need to add a second class to div class "wrapper", but after what I have tried I can't get it to work. I would be nice if someone can help me out with this simple task, but showing me how to do it. I don't have much experience with jQuery, but need it now. </p>