// Window Procedure to circumvent bug(?) in mfc struct CWindowInfo { HWND m_hWnd; WNDPROC m_oldWindowProc; CWindowInfo (HWND hWnd, WNDPROC oldWindowProc) : m_hWnd (hWnd), m_oldWindowProc (oldWindowProc) {} }; extern CMap windowMap; extern LRESULT CALLBACK MySubClassProc (HWND hWnd, UINT nMsg, WPARAM wParam, LPARAM lParam);