LRESULT CALLBACK WindowProc( HWND hwnd,
UINT uMsg,
WPARAM wParam,
LPARAM lParam
);
UINT uMsg,
WPARAM wParam,
LPARAM lParam
);
ms-help://MS.VSCC.v90/MS.MSDNQTR.v90.chs/winui/winui/windowsuserinterface/windowing/windowprocedures/windowprocedurereference/windowprocedurefunctions/windowproc.htm