You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I help you?

USER: I am Pamela Harris. I want to visit a historical place in Boston. Can you book a flight ticket from IAD to BOS?

ASSISTANT: Sure, Pamela Harris, I will help you with that. Can you please share me your travel dates?

USER: I want to travel on 08/21 and 08/23.

ASSISTANT: Please hold for a moment.

USER: Ok.

ASSISTANT: Sorry to say, there are no flights available as per your travel dates.

USER: That's ok. Anyways, thank you for your help.

ASSISTANT: Thank you for reaching us, have a great day.