Attached (q3.c) is what I have so far for a program that plays Xs and Os between you and the computer. The problem is that the program just stops running sometimes and i don't know why! I have a feeling it either has something to do with the computers turn or when either player tries to take a move that has already been taken. Any help would be really really appreciated as I've been working on this for 3 days now and I just can't spot the problem! Sorry for the lack of comments, but its mostly self explanatory.
Thanks in advance,