Taken the rear seat belts out and airbag light is showing

I've taken the rear seat belts out and now my airbag light is on, any idea on what to do? I've read up a little bit and found out I need resistors of some kind can anyone shed some more light on this for me?
 
Strange.. This week I removed my rear seatbelt and I don't have any error light on. Maybe you damaged a wire or connection from the airbag while removing the seatbelts?