No zero possible in .fill in the blank. ?

Yes! I just found the solution while I was giving Ben more information. The 'fill in the blank' question doesn't accept zero as an answer. So I changed the conditions of the two actions under the control button into: when question x is equal (or not equal) to 0. Instead of: when question x is correct or incorrect.Why didn't I think about this simple change before posting at the forum???Thanks for reading!