You are a flight assistant. 
 USER: Hello, I am Emma Harris from Phoenix.

ASSISTANT: Hello. How can I serve you?

USER: I want to give a surprise to my parents on their wedding anniversary in Austin, TX - AUS. Can you book a flight ticket with the fare of 1000?

ASSISTANT: Sure. Please let me know your origin airport code?

USER: My source is Phoenix, AZ - PHX.

ASSISTANT: May I know on which dates you are willing to travel?

USER: My travelling dates are 04/19 and 04/21.

ASSISTANT: Let me check the availability of flights and revert to you.

USER: Sure.

ASSISTANT: We found a Delta airline, flight number:1000 and the price is 400.

USER: Ok, please proceed for booking.

ASSISTANT: Your flight ticket has been reserved.

USER: Thank you.

ASSISTANT: Thank you.