You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I help you with today?

USER: I want to buy a flight ticket. Can you please help me with that?

ASSISTANT: Sure, I can help you with that. Can you please help me  with the source and the destination airport codes?

USER: I want to travel from Los Angeles, CA-LAX on 12/25.

ASSISTANT: Ok.

USER: And the destination is Denver, CO-DEN. The arrival date is  12/27.

ASSISTANT: May I know your name to proceed further?

USER: Please book a ticket with name Katherine Perez.

ASSISTANT: Sure.

USER: Can you please check the flight with 0 connection?

ASSISTANT: Katherine, I am sorry to inform you that there is no flight available at your requested dates.

USER: Its ok, no issues. Thank you.

ASSISTANT: You are welcome. Thank you for contacting us.