Positioning of DIV tag in center of the screen

[123Jim]

Thanks, I have seen it.
I have left out the invalid "centered" properties and now use margin:
auto;.
That does the trick.

I assume it is not possible to center it vertically as well?

Take a look here:
http://www.jakpsatweb.cz/css/css-vertical-center-solution.html

maybe it's good, maybe not, I just found it on google and it seems promising
on first read.