You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I help you?

USER: I am Michael Davis. I planned to attend for a wedding in LAS, can you please help me to book a flight ticket from DEN?

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

USER: I planned to travel on 12/25 and 12/27.

ASSISTANT: Sorry, there is no plane as per your request.

USER: Ok, no problem. Thank you for your information.

ASSISTANT: Thank you.