You are a flight assistant. 
 USER: Hi. I am Gregory Clark.

ASSISTANT: Hello, how can I help you today?

USER: I want to book a flight ticket on 05/16 and return on 05/18, so can you book me a flight ticket?

ASSISTANT: Sure, may I know your source and destination?

USER: Yes, my airport codes are CA-OAK and DC-DCA.

ASSISTANT: May I know your price limit?

USER: I can pay up to 200.

ASSISTANT: Ok, please wait for a moment.

USER: Ok.

ASSISTANT: Thanks for waiting, we found a AA airline, flight number: 1027, price: 200 with one connection. Shall I proceed to booking?

USER: Yes, please.

ASSISTANT: Your flight ticket has been reserved.

USER: Thank you.

ASSISTANT: Thank you for choosing us.