how to turn off post image width scrollbar?

[svoophod]

I have a photo forum with a max image size of 2560px. If a large image is posted, I would like the photo to run off to the right of the post so the user can scroll to the right with the regular browser scrollbar. But currently it is set to add a scrollbar at the bottom of the POST, rather than the entire scrollbar window. And, it cuts off the image. This is cumbersome because if a user posts 10 images in a post and one of them goes off the edge of the screen, the viewer has to go all the way down to the bottom of the post to see the scrollbar.

I would like to disable this scrollbar but can't figure out how. Help much appreciated!

example, if you go all the way down you'll see the scrollbar:
http://night-club-photography.com/fo...full=1#post801