You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, How can I assist you?

USER: I planned to meet my friend in LAS, can you please help me to book a flight ticket from DEN?

ASSISTANT: Sure, May I know the travelling dates?

USER: I prefer to travel on Feb 27 and Feb 29.

ASSISTANT: Do you have any connection limit?

USER: I prefer to travel in a connecting flight.

ASSISTANT: Is there any other requirements?

USER: No.

ASSISTANT: May I know your name?

USER: I am Catherine Taylor.

ASSISTANT: Sorry, No flights found with your chosen dates.

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

ASSISTANT: Thank you for opting us.