How do you make videos automatically play off of internet/youtube?

[Bob]

http://darinwagner.com/2012/01/26/tutori...ll-screen/

I want a special moving background and i have found away to make my background what will appear on any web page i choose the thing is though when i choose a youtube video url for my background it plays normally and when i do what the link above tells me to the video doesn't automatically play and i am left with just a picture for a background

How can i make a full screen video play automatically(without me having to push the unpause button)

[Cold Winter Night]

Auto play