You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I help you today?

USER: I am planning to travel Denver-DEN to enjoy the holidays in Mountain Park, can you book a ticket from New York- JFK?

ASSISTANT: That's good idea, could you please provide me your travel dates?

USER: The trip dates that I am planning is on 03/23 and after that return back on 03/25.

ASSISTANT: May I know your name please?

USER: Sure, my name is Nicholas Robinson.

ASSISTANT: Sorry Nicholas, there are no flights available to DEN on 03/23.

USER: Ok, that's fine, thank you for searching the flights.

ASSISTANT: Thank you for choosing us, have a safe journey.

USER: Thank you.