You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I render you today?

USER: Please book my ticket in a business class.

ASSISTANT: Sure, may I know your good name?

USER: Rachel Johnson here.

ASSISTANT: Could you please share your journey locations?

USER: My trip dates are Sept 17 and Sept 19.

ASSISTANT: Do you prefer a stopover in between your journey?

USER: I need a connecting flight.

ASSISTANT: Is there any other specifications?

USER: No.

ASSISTANT: Please help me with your journey airport codes.

USER: I want to travel from DTW to OAK.

ASSISTANT: Sorry, there are no flights are available as per your requirements.

USER: No problem, thank you.

ASSISTANT: Thank you for opting us.