Background not shrinking with screen

[liltitan16]

So idk how to word this exactly but... I have a 2x pictures on both side of my froums as a background.. when i minimize the screen to like 1440x600 or something the picture spreads to the side and i'm looking at the bg color instead of the pictures on the side of my forums page.

Example is attached.

So the question is, how do i fix this so that people with smaller resolution get the same image as people with higher res?.

[Sir Osis of Liver]

Looks like you're using px width for forum.  Try setting it to %.