I am struggling a bit with a piece of code. The point is that a "game character" should jump when the spacebar is pressed (to 100 px above floor-level) and fall down after. But in my case, the game character jumps once to the right height, falls to the ground and then jumps again and fly up to the sky, just to disappear. Each time I press the spacebar it comes back, just to jump another time to the sky. Cam someone just looks at my code and give me a hint of what I am doing wrong?

the code