You are a flight assistant. 
 USER: Hello, I am Patrick Allen.

ASSISTANT: Hello, how may I support you today?

USER: I would like to attend a meeting with my client in Fisher Building at Boston. Can you book me a plane ticket on dates from 01/16 to 01/18.

ASSISTANT: Sure, I will help you with booking. Please share me your source and destination airport cods?

USER: i would like to board at DCA and land at BOS.

ASSISTANT: May I know your connection limit?

USER: Yes, I need a single lay by.

ASSISTANT: Thank you for the details, please wait for a moment.

USER: Ok.

ASSISTANT: Thank you for waiting, sorry there is no flight available on your journey data.

USER: That's Ok, thanks for your assistance.

ASSISTANT: Thank you for visiting us.