My wife is a writer. We live in NJ, but she gets paid for some jobs from CA. We have a W2 with two state entries:

California

Box 15 = CA, filled with employer state ID number

Box 16 = wages entered

Box 17 = state income tax entered

NJ 

Box 15 = NJ, filled with employer state ID number

Box 16 = blank

Box 17 = state income tax entered 

Turbotax is telling me that we need to have box 16 entered to file electronically. For the purposes of the Federal, i made it 0 and the refund amount didn't change so I submitted it. But, what do I do for NJ?

Thanks!