Change height-top of item when hover

Change height-top of item when hover

I want to create a menu. When I hover, height-top of item will change like

But real my menu like

here is my jsfid http://jsfiddle.net/8vyUg/
<div id="menu">
<ul>
<li><a href="#">Who</a></li>
<li><a href="#">What</a></li>
<li><a href="#">Where</a></li>
</ul>
</div>
How to do that thank!