CSS dl dt dd:hover

So I'm a newbie on the CSS side; and here is a test I made:

http://testing1.atwebpages.com/

Now notice how when you drag your mouse over the navlinks, a box appears. Now I wanted to have that box appear at the top right side. Whenever someone drags their mouse on a certain link; the description appears on the top right header.

I achieved so by positioning the box with a pixel value; however when I do so; the box moves around when the browser window is resized. Can anyone give me a CSS/HTML solution for this?

Edited May 27, 201115 yr by kernel89