content: sub init()
      m.top.backgroundURI = "pkg:/images/purplebg.jpg"
      m.groupButton = m.top.findNode("groupButton")
      m.rectangle = m.top.findNode("rectangle")
      m.groupButton.buttons = ["OK","Cancel"]
      m.groupButton.observefield("buttonSelected","onButtonSelected")
      m.top.setFocus(true)
  end sub
  
  function onButtonSelected()
      if m.groupButton.buttonSelected = 0
          m.rectangle.color = "0xFF0000"
      elseif m.groupButton.buttonSelected = 1
          m.rectangle.color = "0xffffff"
      end if
  end function