jQuery slideToggle variable duration
<p>I have a function where I want the speed of the slideToggle to be dependent on how many children/list items are in the list "<code>$(this).prevAll('.list_category:first')</code>". Can someone tell me where I'm being stupid?</p>

<pre><code>$(".expand").click(function() {
var iNum = $(this).prevAll('.list_category:first').length();
var tNum = iNum*100;
    $(this).prevAll('.list_category:first').slideToggle(tNum, function(){
</code></pre>
