content: sub main() 
      setupScreen()
  end sub
  
  sub setupScreen()
      screen = CreateObject("roSGScreen")
      m.port = CreateObject("roMessagePort")
      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