Introduction (Jumping up problem)

Hi there, my name is colette and i am lucky enough to be owned by an English Springer Spaniel, Cassie. She is Two years old and adorable. I am currently having a few problems with her though. She tends to take me for a walk when we go out, she is great at recall, toilet trained in 2-3 days behaves impecably at home but jumps up on people all the time. I cant figure out how to stop, any ideas anyone? Would be much appreciated. Thank you.