IE7 behaves strangely when we talk about z-index. It doesn’t always respect the z-index values of our elements. However, if you come around this weird stuff, just add a higher z-index to the parent of the element you want to put above everything else. Don’t ask me why this works but it does!
Lets take a look at a small example:
<div style="z-index: 3000"> <div style="position:absolute;z-index:1000;"> this element will appear above everything else <a href="#">Page</a> ... </div> </div>