You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: I am Sandra Allen.

ASSISTANT: How may I aid you today?

USER: I am fascinated by the history of Boston, I want to visit this place.Can you help me to book a ticket from DCA to BOS?

ASSISTANT: I am happy to help you with that, can you please share your journey dates?

USER: I want to fly on 10/22 and 10/24.

ASSISTANT: Wait for a minute.

USER: Sure.

ASSISTANT: Sorry to say that there is no flight found for you.

USER: That's ok. Thank you for your help.

ASSISTANT: Thank you for reacting us.