Settings of Kubrick “theme functions” – Line 14!

I was experimenting a bit with the theme functions and now an error is coming up for my whole site. I just want it back to the original template, but I have an error in line 14.

I’m right here….

$output .= “#header { background: url(”) no-repeat bottom center; }\n”;

Something is supposed to be within the url (”) brackets and I can’t remember what, please please help!