use jQuery to ask if div got a background image?
<p>Is it possible to use jQuery to check if #page has got a background image - #page could look like this:</p>

<pre><code>&lt;div id="page" style="background-image: url(xxx)"&gt;&lt;/div&gt;
</code></pre>

<p>if it contains a background image, it should add a class to #page</p>
