You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I help you?

USER: I am Robert Lee, can you please help me in booking my flight ticket to CLT from JFK in an economy class?

ASSISTANT: May I know your desired travel dates please?

USER: My travel dates are Oct 11 and Oct 13.

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

USER: Not a problem, anyways thank you for the information.

ASSISTANT: Thank you for opting us.

USER: You are welcome.