second click beats first animate complete callback function
<p>I have a button, when clicked, animates a div.</p>

<p>I am trying to make use of the <a href="http://api.jquery.com/animate/" rel="nofollow">$.animate()</a> [complete] callback function, but running into a situation where clicking the button twice really fast causes the animation to run twice before the first animation's [complete] callback runs.</p>

<p>Please see this link for demo.
<a href="http://jsfiddle.net/zs2uf/3/" rel="nofollow">http://jsfiddle.net/zs2uf/3/</a></p>

<p>Any ideas how to prevent the second click from beating the first's callback?</p>
