content: sub Main()
  	thing = invalid
  	try
  		print thing.property
  	catch e
  		print "error"; e.number
  	end try
  	print thing?.property
   	print thing?@field
   	print thing?.functionCall2?()
   	print thing?[0]
   	print thing?[0]?.property
   	print thing?[0]?.functionCall2?()
    	print thing?.functionCall?(thing?[0]?.property, thing?[0]?.functionCall2?())
  	di = CreateObject("roDeviceInfo")
  	try
  		print di.action()
  	catch e
  		print "error"; e.number
  	end try
  end sub