content: sub RunUserInterface()
      print "launching application ..."
      
      ' we will need somewhere for our screen to send event messages
      m.port = CreateObject("roMessagePort")
      
      ' create our scene graph canvas
      screen = CreateObject("roSGScreen")
      screen.setMessagePort(m.port)
      
      ' set the initial scene
      scene = screen.CreateScene("foo")
      
      ' show our canvas
      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