You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I help you?

USER: I am Michelle Parker. I want to book a ticket from SFO to LAX.

ASSISTANT: Sure, I will help you out. May I know travelling dates?

USER: My travelling dates are 12/09 to 12/11.

ASSISTANT: Please wait a moment.

USER: Sure.

ASSISTANT: Sorry, there are no flights.

USER: That' s fine.

ASSISTANT: Thank you for approaching us.

USER: Thank you.