The way you have it is, char question;. This is fine, but a single char only holds one character.
So you have two options, have the user enter either 'Y' or 'N' like:
Or, you can have a character array:
cout << "Go again?(Y/N): ";
cin >> question;
while(question == 'Y' || question == 'y');
You need the cstring header file for strcmp, and you use the getline() member function of cin for char arrays, that way you read the amount of characters you want.
cout << "Enter yes to do it again: ";
Also you need to have 1 extra element in your array for a null terminator.
Hope that helps.