You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I help you?

USER: I am Timothy Wright. I want to visit Oakland in this month so can you please help me in flight ticket booking process from AUS to OAK?

ASSISTANT: Sure, may I your travelling dates?

USER: Thank you for your response, I want to take off on Aug 10 and book my return ticket also on Aug 12.

ASSISTANT: Can I know at what time do you want to depart and return?

USER: I would like to return in evening time.

ASSISTANT: Can I know your class preference?

USER: I am ok with any class.

ASSISTANT: Sorry, there are no flights available.

USER: Oh! It's ok no problem. Thank you for your information.

ASSISTANT: Thank you for choosing us.