You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello.

USER: Brian Walker here.

ASSISTANT: How may I help you Brian?

USER: I want to attend a birthday party in New York. Will you please book my ticket?

ASSISTANT: Ok, can you provide me New York airport code?

USER: Airport codes are SFO and LGA.

ASSISTANT: May I know your travelling dates?

USER: I want to depart on 12/09 and return by 12/11.

ASSISTANT: There is a flight with 1 connected flight which costs 200. Flight 1003 in AA airline.

USER: Ok, please proceed for booking.

ASSISTANT: Shall I book it for you? Your booking is done.

USER: Thank you for your service.

ASSISTANT: Thank you for choosing us.