title: jQuery change class name
body: <p>I want to change the class of a td tag given the td tag's id:</p>
  
  <pre><code>&lt;td id="td_id" class="change_me"&gt; ...
  </code></pre>
  
  <p>I want to be able to do this while inside the click event of some other dom object.  How do I grab the td's id and change its class?</p>