You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I aid you for today?

USER: I am looking to book a  flight ticket from DCA to BOS. Can you help me for that?

ASSISTANT: I am here to help you about that. Can you please provide your planned dates of journey?

USER: My travelling dates are Dec 17 and Dec 19.

ASSISTANT: Do you need any connecting flight for your journey?

USER: No.

ASSISTANT: Can you please provide your name for further proceeding?

USER: My name is Sharon Wright.

ASSISTANT: Do you need any other requirements for your journey?

USER: My depart time is evening.

ASSISTANT: Sorry to say this Sharon Wright, there are no flights to your region on your planned dates of journey.

USER: That's ok, thank you for checking.

ASSISTANT: You are welcome, thank you for reaching us.