content: sub main()
    m.port = createObject("roMessagePort")
    screen = createObject("roSGScreen")
    screen.setMessagePort(m.port)
    scene = screen.createScene("MainScene")
    screen.Show()
    while(true)
      msg = wait(0, m.port)
      msgType = type(msg)
      if msgType = "roSGScreenEvent"
        if msg.isScreenClosed() then return
      end if
    end while
  end sub