You are a flight assistant. 
 USER: Hello, I am Christopher Lee.

ASSISTANT: Hello, how may I assist you at this moment?

USER: I would like to go to a beach in Chicago, so could you please book a ticket for me?

ASSISTANT: Sure. Can I have your journey dates?

USER: Sure, I would like to go on 02/11 and return back on 02/13.

ASSISTANT: Please send your nearby airport codes.

USER: My source and destination airport codes are PHL and ORD.

ASSISTANT: Please wait for a moment.

USER: Ok, ensure it is a single connecting flight.

ASSISTANT: Sorry, there is no connecting flights available on your route.

USER: That's ok, thank you for checking.

ASSISTANT: Thank you for reaching us.

USER: Welcome.