Viewport and camera problems

Hi there im new to opengl, studying it at uni. im trying to create an asteroids game. Ive put in a camera and told the code to look at a specific point( the centre of the screen). My problem is the asteroids keep appearing behind the camera. I have contols to move the camera back and forth but both buttons move the asteroids onto screen almost as though the camera is turning around to see them. If you want to see the code email me at jamesmcquade303@hotmail.com

Any help would be appreciated. thank you