Litter box training a 5 week old kitten?

I am having a difficult time litter box training my kitten, i have gotten her to use the small home made litter box at least twice the other times when I wasn't fast enough to stop her she will go under a small bed side table. I have tried everything I can think of to get her used to the litter box idea but she keeps going under that table. I have even tried leaving her in the bathroom for a few hours with food and water and she won't use it. The times I have gotten her to use it I've had to hold her by the scuff of her neck in the litter box. What can I do to get her to understand that the litter box is where she goes and not under that table. She is like 5 weeks old.