background

I have read everything here, but for some reason I still can’t get a background image to show up. I have ticked “custom style” in the theme skinning and put in my link to the file which is http://talkingwalls.ca/bg-gray.jpg, then repeat both hor and vert.
So why will nothing show up. I’ve tried every way I can to get an image to show up whether in header or body etc. Nothing comes up.