You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how can I aid you?

USER: I need to book a flight ticket from JFK to DFW to enjoy music festivals.

ASSISTANT: Sure, can you share your trip dates?

USER: Sure, my journey dates are Aug 19 and Aug 21.

ASSISTANT: Do you have any preferences?

USER: I would prefer a business class.

ASSISTANT: May I know your name?

USER: Sure, Katherine Hall here.

ASSISTANT: Sorry, there is no flight on your given dates.

USER: Ok, no issues. Thank you for your assistance.

ASSISTANT: Thank you for choosing us.