toupper() or tolower() from <ctype.h> will also simplify expressions like
if (exitquestion == 'Y' || exitquestion == 'y')
if (tolower(exitquestion) == 'y')
if (toupper(exitquestion) == 'Y')
sizeof() never hurt anyone. (If it's an array and not a pointer.)
fgets(exitquestion, 1000, stdin);
fgets(exitquestion, sizeof(exitquestion), stdin);
You should be aware that main() recursion (calling main()) is undefined in C++. It's also somewhat suspicious practise in C -- you should be able to code in such a way that you can use iteration (i.e., loops) instead.
fgets(exitquestion, sizeof exitquestion, stdin);
exitfunction() should return void! Do away with the ancient, deprecated implicit int rule!
Also consider better indentation . . . .
/* ... */
Debatable . . . [/edit]