WinDefImeWindwoProc
This is the window procedure for the IME Window. IME Window should use this default procedure instead of WinDefWindowProc. WinDefImeWindowProc dispatches the IME related messages to the default part windows. IME Window should not pass IME Related message s if IME does not want default action for those messages. For the default actions of the part windows, refer to the later section.
WinDefImeWindowProc's calling syntax is as follows.
MRESULT APIENTRY WinDefImeWindowProc( HWND hwnd, ULONG msg, MPARAM mp1, MPARAM mp2 );