Do I have the new belt on right?

I have a Craftsman Model#917.255950 lawn tractor that was given to me by an in-law. My wife acccidentaly threw the owners manual away, so I'm working a little on the blind side. The drive belt broke recently and I bought a replacement. Without a schematic, I put the belt on the way it seemed to follow with all the wheels and pulleys, but now the gears have switched. Instead of 3 forward gears and 1 reverse, I have 3 reverse and one forward and it's the low gear. Would replacing the drive belt improperly cause this or is there something else wrong that might have occurred when the original belt broke while in use? Is there some place to get a schematic of how the belt is correctly installed? The Sears' website shows the belt, but not the proper placement. This makes for a long mow when you have over an acre to do.