Press space to start it. Here are the other controls: Left Arrow: Changes Position 2 % by 1 Right Arrow: Changes Position 1 % by 1 Up Arrow: Sets Position 1 % to 100, then changes it by -1, until it gets Position 2 % to 100. Down Arrow: Same as Up Arrow, except starts at Position 2 and goes to Position 1.
I made this in my spare time.