You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I aid you?

USER: Please book me a ticket from AUS to CLT to meet my family.

ASSISTANT: May I know your trip dates?

USER: I have planned to travel on Sept 18th and return on Sept 20th.

ASSISTANT: Do you have any other specifications?

USER: I would like to return at afternoon time.

ASSISTANT: Do you need any class preference?

USER: Yes, I like business class.

ASSISTANT: May I know your name?

USER: Myself Margaret Taylor.

ASSISTANT: There are no flights available on your request.

USER: Ok, no problem. Thank you.

ASSISTANT: Thank you for choosing us.