Unity 2d controller script, rigidbody2d gravity not working

Hello, I have a controller script below for my 2D game. When I jump I continue to go up, instead of down after the jump climax. Any help would be appreciated! ![alt text][1] [1]: /storage/temp/45307-jumperror.png It's basically making an invisible button on the screen in which, when you click it it makes the player jump. But the player just keeps going skyward.... and never comes down. This is just part of the script not the whole thing I declared all the variables etc.