You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I help you today?

USER: Can you please help me to book a flight ticket from LAX to LAS?

ASSISTANT: Sure, let me know your planned dates.

USER: My travelling dates are Dec 17 to Dec 19.

ASSISTANT: Is there any connection limit for you?

USER: I need a single connection of flight.

ASSISTANT: Can I have your name please?

USER: My name is Debra Roberts.

ASSISTANT: Do you have any other concerns?

USER: I want to depart in the afternoon.

ASSISTANT: We found a connecting flight with a fare of 100 in 1022 United Airline, shall I proceed?

USER: Please make sure that I would like to prefer business class.

ASSISTANT: Sorry, no flight were found in business class.

USER: No problem, thanks for your information.

ASSISTANT: Thank you for choosing us.