Can anyone tell me what happened with Joe Biden and his wheelchair-bound friend?

Someone told me that Joe Biden was giving a speech or something, and his friend, who is in a wheelchair, was there. Supposedly, Joe Biden asked him to stand up for some reason, and then couldn't understand why everyone was laughing at him. Did this really happen? I may not have all the details right; I couldn't find anything about it online.

Public Comments

1. YES IT DID HAPPEN THEY WERE CAMPAIGNING AND THERE WAS A MAN IN A WHEEL CHAIR AT THE SPEECH AND I THINK HE WAS TRYING TO USE THIS GUY TO MAKE SOME KIND OF A POINT AND HE DID SAY TO THE GUY TO STAND UP CHUCK STAND UP AND TAKE A BOW STAND UP CHUCK. BOY WHAT A PUTZ,HE WARES THAT NECKTIE TO KEEP THE FORESKIN FROM COMING UP OVER HIS HEAD . BUT YES HE DID SAY THIS AND I HEARD HIM SAY THIS.
2. The incident happened back in Sept. Biden was in Missouri. He asked State Senator Chuck Graham to stand up. He kept saying, "Stand Up Chuck, so people can see you." He did not realize that Graham was a parapalegic. I don't think many people were laughing at the time. Biden does have a habit of speaking before thinking.
3. That was the most hilarious comment on the campaign trail, but everyone was so intent on screwing Palin that it was just brushed aside. But I did see it on CNN. He said stand up and take a bow, but the guy was in a wheelchair, what a moron.
4. What happened? Joe Biden is an idiot that's what happened.