anchor.diff:    (declare (ignorable pane))
     (setf (gadget-value button :invoke-callback t) t))
   
  -(defmacro with-radio-box (&body body &rest options)
  +(defmacro with-radio-box (&rest options &body body)
     `(make-pane 'radio-box ,@options
   	      :current-selection (first ,body)
   	      ,@body))
  
positive.code:       (armed-callback pane (gadget-client pane) (gadget-id pane)))
      (setf armed ':button-press)
      (setf (push-button-show-as-default-p pane) t)
      (push-highlight-button pane)))
  
  (defmethod handle-event ((pane push-button-pane) (event pointer-button-release-event))
    (with-slots (armed) pane
  
negative.code:   (with-slots (armed) pane
      (unless armed
        (setf armed t)
        (unless (gadget-value pane)
  	(setf (gadget-current-color pane) (gadget-highlighted-color pane))
  	(dispatch-repaint pane (sheet-region pane)))
        (armed-callback pane (gadget-client pane) (gadget-id pane)))))
  
  (defmethod handle-event ((pane toggle-button-pane) (event pointer-exit-event))
  