The Problem:
You need to give an element a minimum height and you need to work in both FireFox (FF) and Internet Explorer (IE).
The Solution:
In your default style sheet use the declaration below. This will be picked up by Firefox.

min-height:500px;

In your conditionally included style sheet for IE set this declaration.

height:500px;
overflow:visible;

That’s it!

CSS, FF, FireFox, Height, IE, Internet Explorer, Minimum Hide