content: sub main()
      screen = CreateObject("roSGScreen")
      m.port = CreateObject("roMessagePort")
      screen.setMessagePort(m.port)
  
      scene = screen.CreateScene("MainScene")
      scene.backgroundColor="0x000000"
      scene.backgroundUri = ""
      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