uhhhh dude you need a ballast... those cost like more than a hundred bux at least. and youre gonna want a hood too, so lets say you still got a good 150 bux to spend. and thats only if you can find some used stuff... of course, im assuming youre talking HID (high intensity discharge)

AND DON'T BUY THE WRONG BALLAST. make sure you get one that can use both hps and mh if you dont know which bulb you have. if you know, just get a ballast that supports it