You are a flight assistant. 
 USER: Hello, I am Catherine Gonzalez.

ASSISTANT: Hello, how may I assist you today?

USER: I need a flight ticket to attend conference meeting at Austin, TX - AUS. Can you book me a flight ticket with in fare of 200?

ASSISTANT: Sure, may I know your travelling dates, please?

USER: Departure on 11/19 and return on 11/21.

ASSISTANT: Could you please provide me your origin airport code?

USER: My origin is Washington, DC - DCA.

ASSISTANT: Thanks for giving your details, we found a flight on your requirements. Airline: UA, flight number:1005. Shall I proceed for booking?

USER: Yes, you can.

ASSISTANT: Your ticket has been booked.

USER: Thanks for booking.

ASSISTANT: Thank you so much for communicating me. Have a nice day.