You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: I am Brian Lewis.

ASSISTANT: How may I assist you today?

USER: Can you please help me in booking a flight ticket from Washington, IAD to Austin, AUS?

ASSISTANT: Sure, let me know your travel dates please?

USER: My journey dates are from Aug 29 to Aug 31.

ASSISTANT: Do you prefer economy or business class?

USER: I am comfortable with any class.

ASSISTANT: Do you need a stopover?

USER: I need a stopover in between journey.

ASSISTANT: At what time do you want to depart and return on?

USER: My departure time is afternoon.

ASSISTANT: Sorry to say that, there are no flights available on the routes of your journey.

USER: That's ok, not a problem. Thanks for your information.

ASSISTANT: Thank you for reaching us.