GtkDialog::add_button
GtkWidget add_button(string
button_text, int
response_id);
You may use this method to manually add a button to the
action_area property of the Dialog. Of course, you
may also add buttons after you have called the constructor with
buttons. You may add a custom button or a stock item, depending on
whether you pass a stock-ID or plain text as the string parameter. The
response signal may also be indicated as given in
GtkResponseTypes.
The created button is returned as a widget by this method, but mostly
you wouldn't need to use it.