Heli test page

I'm trying to change this page's background, like a page i saw from a different Wiki.


 * Attemp #1: I follow this page, actually i just copy 100% the code and nothing happen.
 * Attemp #2: Wait, i read the thing wrong, don't mind me.
 * Attemp #13: Finally, now i know how to add a background that fit the whole screen, sounds like a 3 years old child.