How to set background position to fixed?

[Sharingan_Okami]

I was messing with inspect element to try and see if i could make my background fixed, but every time i add that to the CSS the forum page doesn't move. I only want the background to be fixed.
forbiddenjutsu.net
If you understand what i mean, can someone please help me out?

[Dave]

Add background-attachment: fixed; to the html element.

[Sharingan_Okami]

That worked :D

Thanks for you help, that was extremely helpful and fast!

[TheLastSuperman]

You can also use cover so it scales, see this for more info:
http://css-tricks.com/perfect-full-page-background-image/