jquery .height() not work in IE9
<p>project_cat is a div, the following code is try to get its height, but all not working in IE9, </p>

<pre><code>jQuery("#project_cat").height();
jQuery("#project_cat").innerHeight();
jQuery("#project_cat").css('height');
</code></pre>

<p>how to get it work in IE9?</p>
