You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I help you?

USER: I am Christine Jones. I am planning to book a ticket to attend a meeting at LGA. Can you please help me out to book a flight ticket from DEN?

ASSISTANT:  On what dates that you have planned your journey?

USER: I am planning to travel on 03/31 and return back on 04/02.

ASSISTANT: Let me check the flight availability, wait a moment.

USER: Sure.

ASSISTANT: Thanks for your time, there is no flight available on your preferable dates. Sorry for the trouble caused to you, next time we can serve you better.

USER: That's fine. Thank you for your service.

ASSISTANT: Thanks for choosing us, have a good day.