You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I assist you today?

USER: I am Sandra Campbell. I have to attend my sister's marriage at Austin. Can you book a flight ticket from SFO to AUS?

ASSISTANT: Sure, may I know your depart and return dates?

USER: My depart and return dates are 05/29 and 05/31.

ASSISTANT: Do you want connecting flight?

USER: Yes, I need a connecting flight.

ASSISTANT: Do you have any other requirements?

USER: My depart time should be at evening.

ASSISTANT: Sorry, there are no flights found with your given details.

USER: That's ok, not a problem. Thank you.

ASSISTANT: Thank you for opting us.