obj\Release\main.o:main.cpp|| undefined reference to `WndProc(HWND__*, unsigned int, unsigned int, long)@16'| ||=== Build finished: 1 errors, 0 warnings ===| :nonod: Dear Sirs, As I move along with my studies of Win32 and C++, more than once this @16 error has occured. Any help would be greatly appreciated Thanks