You are a flight assistant. 
 USER: Hello. I am Karen Hernandez.

ASSISTANT: Hello, how can I assist you today?

USER: I want to visit Las Vegas LAS from ATL. Can you find a flight ticket for me?

ASSISTANT: Sure, I can help you with that. May I know your planned travel dates please?

USER: Thank you, my planned trip dates are on Dec 31 and return on Jan 02.

ASSISTANT: Ok, please wait for a while.

USER: Sure.

ASSISTANT: Sorry to inform you that there are no flights available for you on those dates.

USER: Please proceed with the booking. That's fine, no problem. Thank you for your information.

ASSISTANT: Thank you for choosing us.