Col E Contributions PreTaxed NJ 1040

[vineet]

I had 401k at my previous employer, and I bought in all the amount to an IRA. Now I converted a part of that IRA  to Roth IRA. On column E of NJ 1040 how do i know what amount was tax paid when contributed towards 401k  and what amount I need to pay NJ taxes . How do I calculate this amount. I don't have a basis calculated. Please help. Thanks.

Regards