title: .attr('class') is undefined on jQuery()
body: <p>I've got a problem with my jquery function in a wordpress theme. I've used exactly this function severeal times and it worked. The function returns the ID of an Image, that was uploaded via the wordpress uploader.</p>
  
  <p>Here is the relevant part:</p>
  
  <pre><code>// extract the img-ID from class attribute
  var jt = jQuery('img', html).attr('class');
  alert(html);
  alert(jt);
  j1 = jt.split(' ');
  </code></pre>
  
  <p>Both alerts are only there to figure out, what happens. alert(html) returns this:</p>
  
  <pre><code>&lt;img src="http://www.xyz.com/files/2012/03/stage.jpg" alt="" title="" width="1000" height="371" class="alignnone size-full wp-image-6" /&gt;
  </code></pre>
  
  <p>but alert(jt) returns "undefined".</p>
  
  <p>Any Idea? It would be great, if you could help.</p>
  
  <p>Jan</p>