You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I help you?

USER: I have planned to attend my friend marriage at Chicago -ORD. Could you please help me out with booking a flight ticket from DEN.

ASSISTANT: Sure, let me know your trip dates.

USER: My planned travel dates are from 12/24 to 12/26.

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

USER: That's ok, no problem. Thank you for searching.

ASSISTANT: My pleasure. Can I know your name?

USER: Myself Benjamin Hall.

ASSISTANT: Thank you.