You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I help you?

USER: I am Pamela Edwards. Can you please book a flight ticket from AUS to SFO?

ASSISTANT: Sure, may I know your trip dates please?

USER: Sure, I need to travel on dates of Jan 08 and Jan 10.

ASSISTANT: Can I know your class preference?

USER: I am ok with any class.

ASSISTANT: Sorry to inform you that there is no flight available as per your request.

USER: Oh! It is sad to hear. Anyway, thank you for your time.

ASSISTANT: Most welcome.