PLEASE HELP!!!

Ok, I have a free journal...I'm using the disjointed style. Ok, now...my background image...I can't get it to fit the full window, even though I saved it as a full window, and put it on my image host (Photobucket) as a full window image. I was wondering if someone could please help me and tell me how to fix it because I'm seriously out of ideas...THANK YOU SO MUCH!