content: sub init()
      m.dataGroup = m.top.findNode("dataGroup")
      m.focusRing = m.top.findNode("focusRing")
      m.top.observeField("focusedChild", "onFocusChange")
  end sub
  
  sub onFocusChange()
      if m.top.hasFocus()
          m.focusRing.visible = true
      else
          m.focusRing.visible = false
      end if
  end sub
  
  
  