scrollHeight
is a property of a DOM object, not a function:
Height of the scroll view of an element; it includes the element padding but not its margin.
Given this:
<div id="x" style="height: 100px; overflow: hidden;">
<div style="height: 200px;">
pancakes
</div>
</div>
This yields 200:
$('#x')[0].scrollHeight
For example: http://jsfiddle.net/ambiguous/u69kQ/2/ (run with the JavaScript console open).