You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I assist you today?

USER: Can you please book a flight ticket in business class to attend a meeting in Austin?

ASSISTANT: Sure, I will help you to book a flight.

USER: Thank you.

ASSISTANT: May I know your good name?

USER: Sure, this is Christopher Taylor.

ASSISTANT: Please share me your source and destination airport codes?

USER: My source and destination airport codes are, SFO to AUS.

ASSISTANT: Please mention when you planned to travel?

USER: My journey dates are, depart on Jan 18th and intend to return back on Jan 20th.

ASSISTANT: Do you like to travel in connecting flight for this journey?

USER: Yes, I would like to prefer connecting flight for this journey.

ASSISTANT: Is there any preference related to flight timing?

USER: Yes, flight depart time should be in the evening.

ASSISTANT: Do you have any other requirement?

USER: No, I don't have any other requirements.

ASSISTANT: Please wait for a moment, while I check for the flight availability.

USER: Sure.

ASSISTANT: Thank you for waiting, sorry there is no flight available on your given journey data.

USER: Ok, no problem. Thank you.

ASSISTANT: Thank you for visiting us, we hope see you again.