Scratch

I have a problem with my  Beer Pong App aka Sprite Pong for those younger people on here, but lets get to my problem. I have a sprite appear when you get 50 points in my game. An once you hit 50 this sprite appears and once the ping pong ball hits this sprite I want to have the game end or at least have it restart. I've tried "When Up Arrow Key is pressed" "if touching Sprite11" and " broadcast gameover", all of these I put together. The problem there is that I want the up arrow key to be pressed once and then hit the sprite without pressing the up key more than once for this to happen properly, so what should I do? Can anyone help me????