clearInterval not working as expected
<p>I have the following bit of code which is used to rattle divs.  </p>

<p>I use clearInterval to stop the rattling but it doesn't appear to work.</p>

<p>Any idea why please?</p>

<pre><code>squares = $('.' + square_class); 
var rattle; 

 rattle = setInterval(function() {
 squares.delay(2000).effect('shake', { times:4, distance: 5 }, 100);
 }, 2000);

clearInterval(rattle);
</code></pre>
