title: chrome and css issue
body: <p>I have this html code</p>
  
  <pre><code>&lt;div id = 'status'&gt;
  &lt;span class="formw" style="background-color:#FBD9E5;"&gt;
  some text
  &lt;/span&gt;
  &lt;/div&gt;
  </code></pre>
  
  <p>When the following javascript gets executed</p>
  
  <pre><code>$('status').style.backgroundColor = '#99e83f'; 
  </code></pre>
  
  <p>chrome throws the following error:</p>
  
  <pre><code>Uncaught TypeError: Cannot read property 'style' of null
  </code></pre>
  
  <p>Anybody knows the reason?</p>
  
  <p>Update: I am using Prototype.</p>