content: sub Main()
      screen = createObject("roSGScreen")
      m.msgPort = createObject("roMessagePort")
      screen.setMessagePort(m.msgPort)
  
      main = screen.createScene("Main")
  
      ' use #222222 as the background color, which requires assigning an empty string as the background URI
      main.backgroundUri = ""
      main.backgroundColor = "0x222222ff"
      screen.show()
  
      while(true)
          msg = wait(0, m.msgPort)
          msgType = type(msg)
  
          if msgType = "roSGScreenEvent"
              if msg.isScreenClosed() then return
          end if
      end while
  end sub
  