void SetModify( BOOL bModified = TRUE );
bModified
A value of TRUE indicates that the text has been modified, and a value of FALSE indicates it is unmodified. By default, the modify flag is set.
Sets or clears the modification flag for an edit control. The modification flag indicates whether or not the text within the edit control has been modified. It is automatically set whenever the user changes the text. Its value may be retrieved with the GetModify member function.
CEdit::GetModify, EM_SETMODIFY