You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I assist you?

USER: Please book a flight ticket from SFO to MSP?

ASSISTANT: Sure, may I know your planned travel dates please?

USER: My journey dates are Apr 25 and Apr 27.

ASSISTANT: Would you like to travel in a connecting flight or a direct flight?

USER: I need a connecting flight.

ASSISTANT: Do you have any class preference?

USER: I prefer a business class.

ASSISTANT: Do you have any particular time for departing and returning?

USER: No.

ASSISTANT: Do you have any airline preference?

USER: No.

ASSISTANT: May I know your good name please?

USER: I am Karen Young.

ASSISTANT: Sorry, there is no flight available for your request.

USER: No problem, thank you for your information.

ASSISTANT: Thank you for reaching us.