You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how could I assist you today?

USER: I am Virginia Allen. I want to visit mesuem at Charlotte, CLT. Can you please book a ticket from San Francisco, SFO?

ASSISTANT: Sure, how much you can afford for the flight ticket?

USER: Price limit is 5000.

ASSISTANT: OK, may I know your preferred travelling dates?

USER: Travelling dates are 02/05 to 02/07.

ASSISTANT: There are no flight found on your requested dates.

USER: No problem. Thank you.

ASSISTANT: Thank you for approaching us.