You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I help you?

USER: Can you help me in booking a flight ticket from SFO to AUS?

ASSISTANT: May I know your desired travel date please?

USER: I want to travel on 09/13, and return on 09/15.

ASSISTANT: Do you have any specifications?

USER: I want to depart in the evening time.

ASSISTANT: May I know your name please?

USER: I am Ruth Robinson.

ASSISTANT: Sorry to say, there is no flight on your desired travel dates.

USER: Ok, no issues. Thanks for the information.

ASSISTANT: Thank you for opting us.