Background design for webpage?

I am trying to create a background design for my webpage but I cannot figure out what size design I create in Photoshop. How do I get a design that takes up exactly the size of my background. I am using DreamWeaver 4.0 if you need to know that.

Thanks,
Senna

The size of the wallpaper would depend on the resolution at which your visitors run on. Since people's resolutions vary from 800x600 to 1280x960+ it might be hard to figure it out.

hi friend,

can you tell me one thing you are making site ok, but you are designing for which resolution is it for 800x600 if yes then make your background image of size of 780x420..............

and fix that image in to the center of the table.............

this will surely work.............
abhi1