Width of the Background Image on different screens

Hi. I’m wondering if there’s a way to get the background-image on my site to be in the same scale nomatter the size of the screen/monitor people use? I use a 22″ monitor, but on a smaller screen (laptop) I dont get the whole image in sight. Is there a way to auto-fit the image to whatever screen people got? I hop you understand what I mean and know a way to do this. The background image is static by the way. I dont want the image to go along as you scroll down on my page.

Thanks,
Halvformat