I have an 18 month old Blue Nose that jumped on EVERYONE. The way I broke her habit was as she was beginning to jump I would put a string grip on her neck and say no and push down. You have to be extremely consistent or it will not work. I also tell people coming in the door not to let her jump – to use their hand to stop it. Putting up a knee is only blocking it is not correcting so they do not see it as a command. It took her a while, but she eventually got it and as soon as my hand gives her a little bite on the neck she sits. Now it always seems like she wants to jump, but she forces herself to just sit down. I also would move in forward towards her as she was jumping and as I put my hand on her neck to say I am claiming the space and her behavior was not tolerated. Good luck I hope I was some help. I really wanted to stop the behavior b/c I was worried she would eventually knock someone over and it made people nervous.