Dog jumps on people

In most cases this is simply an overexuberant greeting. Correct the problem not by shouting at the dog or "kneeing" (using a knee to deliver a blow to the dog's chest) but by ignoring the behaviour. Make no reaction at all, for good or ill. Just move away from the dog so that is cannot continue. In most cases, the dog will eventually stop. Another alternative is to command the dog to sit when it seems about to jump.