You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, do you need any help from us?

USER: I am Carolyn Williams. Please book a ticket from DTW and PHX to go for Cultural festival.

ASSISTANT: Sure, could you please share your departure and arrival day?

USER: My travelling dates are Dec 10 and Dec 12.

ASSISTANT: Ok, may I know your class preference?

USER: I prefer business class.

ASSISTANT: Ok, do you have any other requests for your journey?

USER: My return time is afternoon.

ASSISTANT: Ok, please allow me a moment.

USER: Ok.

ASSISTANT: Sorry, there is no flight with your requests.

USER: Ok, Thank you.

ASSISTANT: You are welcome, have a great day.