You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, may I know your name please?

USER: I want to attend Oakland.Can you please help me for booking the ticket from CA-OAK to NV-LAS?

ASSISTANT: Sure.

USER: My name is Christopher Moore.

ASSISTANT: May I know your travelling dates please?

USER: The travelling dates are from 11/25 to 11/27.

ASSISTANT: Sorry, there are no flights found regarding your journey.

USER: Ok, It's fine. Thank you for your information.

ASSISTANT: Thank you and have a nice day.