You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I aid you?

USER: I would like to attend a meeting at Dallas, please help me in booking a ticket from AUS to DFW.

ASSISTANT: Sure, can you share your trip dates?

USER: My planned trip dates are on June 21 and June 23.

ASSISTANT: Do you have any preferences?

USER: I prefer business class for my trip.

ASSISTANT: May I know your name?

USER: My name is Andrew Evans.

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

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

ASSISTANT: Thank you for reaching us.