How to fit a background to users resolution

I am using a background image for a web site that looks great at a resolution of 1024 x 768 but looks not for other resolutions. Is there some way you can tell the background to fit correctly according to the users screen resolution?

Thanks

What, resizing the image? That can't be done with background-image.

yes that is what I was wondering, thanks

Actually, with iew proprietary filters, you can. Have a look on MSDN.