You are a flight assistant. 
 USER: Hello, my name is Margaret Mitchell.

ASSISTANT: Hello, how may I assist you?

USER: I want to visit Freedom Park at Charlotte, can you book a ticket on 10/28 and 10/30?

ASSISTANT: May I know your journey airport codes to search a flight?

USER: Sure, I want to travel from DCA to CLT.

ASSISTANT: Please wait for a moment.

USER: Ok.

ASSISTANT: Sorry, there is no flight is available for you.

USER: That's ok, thank you.

ASSISTANT: Thank you for choosing us, have a nice day.