This method enables a control to notify its sink when the control loses focus.
HRESULT HandleLostFocus( IDispatch *pdispControl );
NOERROR indicates that the sink handled the message. S_FALSE indicates that the sink did not handle the message. If an error occurs, the appropriate HRESULT value is returned.
A control invokes this method when its own IASControl::LostFocus method is invoked.
IASControl::LostFocus, IASClassMsgSink::HandleGotFocus.