to have a scrolling div, all you need to do is assign a height to it.
ex:
CODE
<style type='text/css'>
#div {
position: absolute;
width: 400px;
height: 400px;
left: ___;
top: ___;}
</style>
<div id="div">blah blah</div>
Once the content gets bigger than the assigned height (400px) it will scroll