You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how can I assist you?

USER: I would like to return from San Francisco on 05/22 after finishing off my work. Can you help me book a flight ticket from Philadelphia on 05/20?

ASSISTANT: Sure, please provide your airport codes.

USER: I intend to leave from PHL to SFO.

ASSISTANT: May I know your name?

USER: My name is Alexander Collins.

ASSISTANT: AA airlines with single connection and price is 100 of 1011 flight.

USER: You can proceed for booking.

ASSISTANT: Your ticket has been confirmed.

USER: Thank you for the booking.

ASSISTANT: Thank you.