You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how may I aid you?

USER: I would like to book a ticket from IAD to ORD.

ASSISTANT: Sure, help me with the trip dates?

USER: Departure is by Sept, 15 and return date is Sept, 17.

ASSISTANT: May I know your name please?

USER: I am Samuel Young.

ASSISTANT: Do you have any preferences?

USER: I prefer economy class.

ASSISTANT:  We found an airline: United, flight number: 1014 and price is 100 with one connection. Shall I proceed to book?

USER: Please book a flight.

ASSISTANT: Your flight ticket has been booked.

USER: Thank you.

ASSISTANT: Thank you for reaching us.