afx_msg void OnKillFocus( CWnd* pNewWnd );
pNewWnd
Specifies a pointer to the window that receives the input focus (may be NULL or may be temporary).
Called immediately before losing the input focus.
If the CWnd object is displaying a caret, the caret should be destroyed at this point.
This message-handler member function calls the Default member function. Override this member function in your derived class to handle the WM_KILLFOCUS message.
CWnd::SetFocus, CWnd::Default, WM_KILLFOCUS