You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I assist you at this moment?

USER: I need a business class flight to Charlotte in the month of December to attend an event there. Can you help me in booking a flight ticket from Oakland?

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

USER: Thank you for your concern. My travel dates are Dec 30 and Jan 1.

ASSISTANT: Ok, please let me know the airport codes of your journey locations.

USER: Ok, my airport codes are OAK and CLT.

ASSISTANT: Do you have any other specifications?

USER: I need a connecting flight for my journey.

ASSISTANT: Can I have your good name please to  proceed further?

USER: Ok, my name is Debra Carter.

ASSISTANT: Ok, please wait a moment to check flight availability.

USER: Ok, sure take your time.

ASSISTANT: Sorry Debra Carter, no flight is available to you in business class on your dates.

USER: Not a problem, anyways thank you for the information.

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