def exit_col_remove_mode(self, event):
        """
        go back from 'remove cols' mode to normal
        """
        # close help messge
        self.toggle_help(event=None, mode='close')
        # update mode
        self.remove_cols_mode = False
        # re-enable all buttons
        for btn in [self.add_cols_button, self.remove_row_button, self.add_many_rows_button]:
            btn.Enable()

        # unbind grid click for deletion
        self.Unbind(wx.grid.EVT_GRID_LABEL_LEFT_CLICK)
        # undo visual cues
        self.grid.SetWindowStyle(wx.DEFAULT)
        self.grid_box.GetStaticBox().SetWindowStyle(wx.DEFAULT)
        self.msg_text.SetLabel(self.default_msg_text)
        self.help_msg_boxsizer.Fit(self.help_msg_boxsizer.GetStaticBox())
        self.main_sizer.Fit(self)
        # re-bind self.remove_cols_button
        self.Bind(wx.EVT_BUTTON, self.on_remove_cols, self.remove_cols_button)
        self.remove_cols_button.SetLabel("Remove columns")
go back from 'remove cols' mode to normal