You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I assist you now?

USER: Please book a flight ticket from OAK to DTW?

ASSISTANT: Sure, I will help you with that. Can I have your  travel dates please?

USER: My journey dates are Feb 03 and Feb 05.

ASSISTANT: Ok,  please let me know your preferable class.

USER: I am comfortable with any class.

ASSISTANT: Do you  have any other specifications?

USER: I need a connecting flight.

ASSISTANT: Can I have your good name please?

USER: I am Frank Johnson.

ASSISTANT: Sorry to inform you that no flight is available to you on your  planned dates.

USER: No problem, thank you for your information.

ASSISTANT: Thank  you for choosing us, have a  good day.