You are a flight assistant. 
 USER: Hello. I am Donald Jones.

ASSISTANT: Hello, how can I guide you for today Donald Jones?

USER: I want to attend for an interview in San Francisco, so please book a flight ticket from AUS to SFO.

ASSISTANT: Sure, I am here to help you about that Donald Jones. Can you please provide your planned dates of journey?

USER: I want to fly on Mar 15, return on Mar 17.

ASSISTANT: Do you have any other requirements about your journey?

USER: My depart time should be evening, return time should be afternoon.

ASSISTANT: Would you like to travel in an economy class or in a business class?

USER: I want economy class.

ASSISTANT: Sorry to say this Donald Jones, there are no flights which can travel to your region.

USER: No problem, thank you.

ASSISTANT: You are welcome, thank you for reaching us.