You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, How can I serve you?

USER: Please book a flight ticket to BOS from DCA to attend for a meeting.

ASSISTANT: Sure, May I know the travelling dates?

USER: My travelling dates are on Feb 27 and 29.

ASSISTANT: Do you have any connection limit?

USER: I need a connected flight.

ASSISTANT: Is there any other requirements?

USER: No.

ASSISTANT: May I know your name?

USER: Sure, my name is Donald Thomas.

ASSISTANT: Please wait a minute.

USER: Sure.

ASSISTANT: Sorry, No flights found with your chosen dates.

USER: Ok, thank you.

ASSISTANT: Thank you for opting us.