You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I help you?

USER: I am planning for a holiday vacation on 12/26 from CA-OAK. Can you please help me for booking a flight ticket?

ASSISTANT: Is this a round trip? Will you need a return ticket, too?

USER: No, my destination airport code is NY-LGA and I would like to return on 12/28.

ASSISTANT: Sorry, there are no flights available regarding your travelling dates.

USER: OK, that's fine.

ASSISTANT: May I know your name please?

USER: I am Andrew Hill.'. Thank you for your time.

ASSISTANT: Thank you and have a nice day.