You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I help you?

USER: I'm Alexander Hall. I am planning to attend music concert at IAD, can you please help me with booking a flight ticket from BOS?

ASSISTANT: May I know your desired travel dates please?

USER: Sure, I would like to take off on 02/25 and return back on 02/27.

ASSISTANT: Please wait a while.

USER: Sure.

ASSISTANT: Sorry to say, there is no flight on your desired travel dates.

USER: Ok, no issues. Thank you for checking.

ASSISTANT: Thank you for opting us.

USER: You are welcome.