How to fix:

1. Press the escape (esc) key on your keyboard and click "options".

2.Click "controls".

3.Click on a gray box with a key and it should turn to ???. Then press the key you want that control to be. If the key you pressed is in the box but is red, then that means that 2 controls are that key, which in that case you have to change one of the keys.

Note: Button 1 is your left mouse button. Button 2 is your right mouse button. I have no clue what button 3 is, so if somebody wants they can fill that in for me.