Percent question?

Why cant I get this to work... I need to use a percent but it doesnt do anything if I have it like this... any ideas?

<div id="name" style="position:relative;top:70%;left:50%;visibili ty:hidden">

Thanks for your time.
- Dan

[Admin]

You can't do it like that (as far as I know). You will probably need to use Javascript to get the window size, then create the number of pixels using some formula, then print it with Javascript.