You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: I am Nancy Williams.

ASSISTANT: How can I aid you at this moment?

USER: I have to attend a Music Concert at Denver, could you please help me with booking a flight ticket? I would like to take off on 05/21 and return on 05/23.

ASSISTANT: Sure, can you please provide your nearest airport codes of travelling?

USER: My nearest source airport code is ORD and destination airport code is DEN.

ASSISTANT: Wait a moment please.

USER: Sure.

ASSISTANT: Southwest airlines is available on this route with a ticket fare of 200, shall I book your ticket?

USER: Please proceed with the booking.

ASSISTANT: Nancy Williams, your ticket is booked with flight number 1016.

USER: Thank you for your service.

ASSISTANT: Thank you, have a safe journey.