title: Change class of element in div when div is focused?
body: <p>How do change class of an element inside a div when the parent div is focused?</p>
  
  <p>Like when I am active in the </p>
  
  <pre><code>&lt;div id="window" class="fenster"&gt;&lt;a class="bye"&gt;&lt;/a&gt;&lt;/div&gt;
  </code></pre>
  
  <p>The class of A changes to hello?</p>