Illinois deduction for taxes paid to another state

We had gambling winnings from Mississippi and they withheld the tax we owed. According to my research non-residents do not have to file a Mississippi tax return if they only have gambling winnings in Mississippi. When filling out the information for my Illinois return I can enter the amount withheld but when I move to the next item the amount I entered is removed from the box. When I check the finished return I do not see any credit for Mississippi tax paid. How can I get TurboTax to accept the Mississippi tax I paid as an Illinois credit?

 

Thanks,  Jim