You have lots of points to note in the above code snippets.
1. CheckDisc is a member function of some class Gamecheck
2. You are trying to call it as normal function which is not syntactically correct.
3. You are comparing int with string in the function CheckDisc.
4. cin should be done on a variable and if its done on a function then the return type of the function should be reference. (Just ignore this if you dont understand ) Remember it should be on var as of now.