You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how may I aid you today?

USER: Please help me to book a flight ticket from LAX to DTW.

ASSISTANT: Sure, may I know your travel dates?

USER: My trip dates are from Dec, 25 to Dec, 27.

ASSISTANT: On which name do you like to reserve this ticket?

USER: My name is Nicholas Hall.

ASSISTANT: Do you prefer normal cost or low cost airline?

USER: I prefer normal-cost airlines.

ASSISTANT: Do you have any other preferences?

USER: I need a single connecting flight and I prefer business class to fly.

ASSISTANT: Sorry, there is no flight on your required dates.

USER: No problem, thanks for your information.

ASSISTANT: Thank you.