code: def boolbox(msg="Shall I continue?"
      , title=" "
      , choices=("Yes","No")
      , image=None
      ):
      
      reply = buttonbox(msg=msg, choices=choices, title=title, image=image)
      if reply == choices[0]: return 1
      else: return 0
docs: Display a boolean msgbox.
  
      The default is the first choice.
  
      The returned value is calculated this way::
          if the first choice is chosen, or if the dialog is cancelled:
              returns 1
          else:
              returns 0