You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I assist you?

USER: I am Nancy Moore.

ASSISTANT: Hello Moore.

USER: I want to visit Millennium park in Chicago, could you please help me in booking a ticket from San-Francisco?

ASSISTANT: Sure, may I know your origin and destination airport codes?

USER: My source code is SFO and destination is ORD.

ASSISTANT: Ok, when would you like to travel?

USER: My travelling dates are from 11/03 to 11/05. Make sure I need direct flight only.

ASSISTANT: Sorry Moore, there is no flight with your requested dates.

USER: That's ok. Thank you for your quality service.

ASSISTANT: Thank you for reaching us, have a good day.