Not to go OT but I am someone who does not believe it is fair to "firmly correct" a dog who jumps up. This is a very normal, acceptable doggy behaviour and physically punishing a dog for jumping up is not necessary. If there are only two people who the dog still jumps up on than it should be relatively easy to fix. Just ask those two people to get on board with teaching your dog some people manners. Ask them that when they see your dog not to interact with him at all unless all four of his feet are on the ground. No eye contact, no touching (including pushing him off), just don't react in any way until he is firmly on the floor. Once he is there they can greet him with gentle strokes and soft, unexcited voices. He should learn that to get the greeting and attention he's craving he must first perform a trick...keeping all four feet on the floor. Because, remember, this is a trick. It's not normal for a dog to see a person and remain on the floor, it is something we must teach them.