You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how may I be at your service today?

USER: Could you please book a flight ticket from DCA to BOS?

ASSISTANT: Sure, I will help you in booking the ticket. May I know your travelling dates please?

USER: My trip dates are Jan 28 and Jan 30.

ASSISTANT: Do you have any other specifications?

USER: I need a direct flight. And I prefer an economy class.

ASSISTANT: Please help me with your name for booking.

USER: I am Rachel Carter.

ASSISTANT: Sorry for this inconvenience, I could not find any flight with your requirements.

USER: Not a problem, thank you for the information.

ASSISTANT: Thank you for reaching us.