# File gtk/sample/gtk-demo/appwindow.rb, line 146
    def toolbar_cb(*args)
      dialog = Gtk::MessageDialog.new(self,
                                      Gtk::Dialog::DESTROY_WITH_PARENT,
                                      Gtk::MessageDialog::INFO,
                                      Gtk::MessageDialog::BUTTONS_CLOSE,
                                      "You selected a toolbar button")

      # Close dialog on user response
      dialog.signal_connect('response') do |widget, data|
        widget.destroy
      end

      dialog.show
    end