CSS Background Images
Most likely the problem is the path to your image. Image paths in CSS must be relative to the CSS file and not to the file that's including the CSS file.
So if you're placing this css code in this file path:
osticket/scp/css/
and the image is in this image folder:
osticket/scp/images/
then the shorthand code would include two dots to bring you out of the CSS directory first, and then into the images folder:
body{background:#000 url('../images/bgcarbon.gif') repeat-x;}
Shorthand code is a nice way to declare all of the properties in one line.
Hope that helps!