You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I assist you at this moment?

USER: I am planning to attend a live music concert in Denver, can you please help me in booking a flight ticket from DTW to DEN?

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

USER: My planning dates are Dec 24 and Dec 26.

ASSISTANT: Ok, please let me know the preferable class that you want.

USER: I prefer business class.

ASSISTANT: Do you have any other specifications to travel?

USER: I need a connecting flight.

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

USER: My name is Thomas Garcia.

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

USER: That's ok, thank you for checking.

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