LRESULT CallWindowProc(
    WNDPROC lpPrevWndFunc,
    HWND hWnd,
    UINT Msg,
    WPARAM wParam,
    LPARAM lParam
);
 

 
DECLARE INTEGER CallWindowProc IN user32;
    LONG lpPrevWndFunc,;
    LONG hWnd,;
    LONG Msg,;
    INTEGER wParam,;
    INTEGER lParam