I have this piece of code, from Lesson 5: Switch case.

When I compile it, I get this from VS 2005:
Code:
1>------ Build started: Project: test, Configuration: Release Win32 ------
1>Compiling...
1>test.cpp
1>Linking...
1>test.obj : error LNK2001: unresolved external symbol "void __cdecl playmultiplayer(void)" (?playmultiplayer@@YAXXZ)
1>test.obj : error LNK2001: unresolved external symbol "void __cdecl playgame(void)" (?playgame@@YAXXZ)
1>test.obj : error LNK2001: unresolved external symbol "void __cdecl loadgame(void)" (?loadgame@@YAXXZ)
1>test - 4 error(s), 0 warning(s)
========== Build: 0 succeeded, 1 failed, 0 up-to-date, 0 skipped ==========
any suggestions ?