You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I aid you?

USER: I am planning to celebrate my birthday in Boston, so please book a flight ticket from IAD to BOS.

ASSISTANT: Sure, can you please share your travel dates?

USER: My departure day is July 01, return day is July 03.

ASSISTANT: May I know your connection limit?

USER: I need a single connecting flight.

ASSISTANT: Do you have airline preference?

USER: No.

ASSISTANT: May I know your departure and arrival time?

USER: I am comfortable with any time.

ASSISTANT: Do you have any other requirements?

USER: No.

ASSISTANT: Ok, please share your name to proceed further.

USER: My name is Andrew Brown.

ASSISTANT: Sorry, there are no flights in this route as per your travelling details.

USER: No problem, thank you.

ASSISTANT: Thank you for choosing us.