title: jQuery if a link hasClass, apply a class to its parent
body: <p>I've got a simple list: </p>
  
  <pre><code>&lt;ol&gt;
      &lt;li&gt;&lt;a href="#" class="on"&gt; I'm on&lt;/a&gt; &lt;/li&gt;
      &lt;li&gt;&lt;a href="#"&gt; I'm off&lt;/a&gt; &lt;/li&gt;
      &lt;li&gt;&lt;a href="#"&gt; I'm off&lt;/a&gt; &lt;/li&gt;
  &lt;/ol&gt;
  </code></pre>
  
  <p>I want apply a class to the <code>&lt;li&gt;</code> if the <code>&lt;a&gt;</code> it contains has the class <code>on</code>. </p>
  
  <p>IE:  I want to change from </p>
  
  <p><code>&lt;li&gt;&lt;a href="#" class="on"&gt; I'm on&lt;/a&gt; &lt;/li&gt;</code></p>
  
  <p>to: </p>
  
  <p><code>&lt;li class="active"&gt;&lt;a href="#" class="on"&gt; I'm on&lt;/a&gt; &lt;/li&gt;</code></p>
  
  <p>There's 100 better ways to do this using just css, but all involve refactoring a complicated slider I have setup. If I could use the <code>a.on</code> to affect its <code>.parent()</code>, I'd be all set. </p>
  
  <p>Le fiddle: <a href="http://jsfiddle.net/saltcod/GY2qP/1/" rel="nofollow">http://jsfiddle.net/saltcod/GY2qP/1/</a></p>