You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I aid you today?

USER: I want to book a ticket from AUS to CLT to go for Holiday trip.

ASSISTANT: Sure, I will aid you with that. Can you please mention your preferable travel dates?

USER: My travelling dates are Dec 20 and Dec 22.

ASSISTANT: May I know your name for further process?

USER: Sure, I am Joseph Davis.

ASSISTANT: Do you have any preferences regarding timings of your journey?

USER: My return time is morning.

ASSISTANT: Do you prefer either an economy or business class?

USER: I am comfortable with any class.

ASSISTANT: Do you have any another specifications?

USER: No.

ASSISTANT: Ok, please hold on a moment.

USER: Sure.

ASSISTANT: Sorry, no flights are available in this route as per your requested dates.

USER: Ok, no issues. Thank you.

ASSISTANT: Thank you for reaching us.