Resize image to fit resolution

[_PD_]

Hi,

Really sorry to start a new thread for this - but I can't find it on a tutorial.

Basically, I want a website background image to always fit the screen, no matter what the resolution. How can I do this?
I am sure there must be the relevant code somewhere, and it's probably really simple.

Thanks for any help.

 

[_PD_]

Nooooo, I'm talking about a website background image here.

So when someone with 800x600 resolution visits it doesn't extend off the side of the page, and when someone with a huge monitor and a 1600x1200 resolution visits, it doesn't have a border around the edge.

Basically, I need a script or something which resizes the background image dependant on the visitors resolution.