I can't change a pic in the adm panel?

When I try to change a picture to use as a background of my forum(in the advance section) it doesn't show up and it says there's a problem in the "Host image" or something.What can I do?

p.s.I changed some of them 2 days ago successfully but now it just doesn't work.

try hosting your images on a different website. Try photobucket.com

be sure you are copying the "direct link" to the image

I was using an image from photobucket and I was copying the direct link,but it still didn't work,..

Oh thank you soo much,I guess I was making some kind of mistake.

no problem