You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I assist you?

USER: Please book a flight ticket with business class as for my business meeting purpose.

ASSISTANT: Sure, can I know your name please to proceed further?

USER: Myself George Lee.

ASSISTANT: May I know the travel dates please?

USER: I would like to fly on July 21st and return on July 23rd.

ASSISTANT: Could you please provide the airport codes?

USER: I want to move from LAX to PHL.

ASSISTANT: Do you have any requirements?

USER: I prefer direct flight.

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

USER: Ok, no problem.

ASSISTANT: Thank you for approaching us.

USER: Thank you.