Light/lamp laptop help. who can help me?

My laptop doesnt have a virus. It works fine, just the light on my screen wont come on. I have to use a regular lamp and put it over my screen so that I CAN SEE. EVEN WITH THIS, THE SCREEN IS STILL VERY DARK. i REALLY NEED HELP. CAN THIS BE FIXED? HOW? IM SUE ITS A BATTERY ISSUE BUT IM NOT SURE. PLEASE GIVE ME ANSWERS, NOT SUGGESTIONS. I apologize if there are any typos, but as you can tell by now, I can barely see my screen.