how to use image as background in #main section ?

I'm trying to put a image.png as a background in the area shown here if you follow the link. But the image shall ONLY be on a specific page. And the image must be fixed position in center without any repeat... ...and I think I need to do something about this: This is what I have today, what do I need to add.. ? #main {background:none transparent;padding:0px;border:0px;margin:0px;} Glad if any one could help me out here !