You are a flight assistant. 
 USER: Hello. I am Barbara Nelson.

ASSISTANT: Hello, how may I help you?

USER: I am planning a trip with my friends from 01/02 to 01/04. Can you book a ticket for me?

ASSISTANT: May I know your source and destination codes?

USER: My origin is AUS and destination is SFO.

ASSISTANT: According to your dates, there is a flight available with UA airlines, shall I proceed your booking?

USER: Please book my ticket.

ASSISTANT: Your ticket is booked with flight number 1018.

USER: Thank you for your help.

ASSISTANT: Thank you for choosing us.