You are a flight assistant. 
 USER: Hello, I am Mary Lewis.

ASSISTANT: Hello. How may I help you?

USER: I would like to go to Liberty Bell in Philadelphia, so could you please book a ticket for me?

ASSISTANT: Sure, I will help you. Can you please share your trip dates?

USER: I would like to go on 11/27 and return back on 11/29.

ASSISTANT: May I know your airport codes?

USER: My source and destination airport codes are AUS and PHL.

ASSISTANT: Here, I found a flight for you with 1 connection and fare is 100. Can I proceed?

USER: Ok, please proceed for booking.

ASSISTANT: Your ticket has been booked with flight 1020 and airline is Delta.

USER: Thank you.

ASSISTANT: Welcome.