You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I help you?

USER: I would like to travel from DEN to ATL. Can you please help me in ticket booking?

ASSISTANT: Sure, may I know your trip dates please?

USER: My travel dates are from 09/23 to 09/25.

ASSISTANT: Do you have any other requirements?

USER: I would like to prefer my departure time in the afternoon time.

ASSISTANT: Let me know your name please.

USER: Myself Christine Taylor.

ASSISTANT: Sorry, we regret to inform you that there is no flight available as per your request.

USER: That's ok, thank you.

ASSISTANT: Most welcome.