title: Trying to Update padding-top of a <div> with jQuery
body: <p>I have a <code>&lt;div&gt;</code> that I'm getting the height of, then I want to add 20 pixels to that value to set the <code>padding-top</code> of another <code>&lt;div&gt;</code>.</p>
  
  <pre><code>    &lt;div id="system_message" class="lom_system_message_header"&gt;
          &lt;span style="font-size: 24px"&gt;SYSTEM ANNOUNCEMENT&lt;/span&gt;
          &lt;br&gt;
          Blackboard is currently down.  We\'re working on it.
      &lt;/div&gt;
  
      &lt;script type="text/javascript"&gt;
          var message_height = $("#system_message").height();
          var padding = message_height + 20 + "px";
          alert(padding);         
          $("#system_message_spacer").css("padding-top", padding);
      &lt;/script&gt;
  
      &lt;div id="system_message_spacer"&gt;&lt;/div&gt;
  </code></pre>
  
  <p>It's not working, but the <code>alert()</code> shows as "82px".  When I try <code>$("#system_message_spacer").css("padding-top", "82px");</code> in the Chrome dev. tools it works fine.</p>
  
  <p>What am I missing here?</p>