You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I serve you?

USER: I want to book a flight ticket from AUS to HOU. Could you help me in booking?

ASSISTANT: Sure, I will help you. Please send your travelling dates.

USER: My travelling dates are from Jan 26 - 28.

ASSISTANT: Do you have any preferences?

USER: I prefer for business class with single connection.

ASSISTANT: May I know your name?

USER: Michael Miller.

ASSISTANT: Sorry, there is no flight available as per your class preference.

USER: That's ok, no problem. Thank you.

ASSISTANT: You are welcome, have a nice day.