You are a flight assistant. 
 USER: Hello, I'm Carol Martin.

ASSISTANT: Hello Carol. How may I assist you?

USER: This Christmas I would like to enjoy my vacation with my family in Charlotte, so could you please book a ticket?

ASSISTANT: Sure, please provide me your journey dates.

USER: I would like to travel on 11/05 and return back on 11/07.

ASSISTANT: May I know your corresponding airport codes?

USER: My airport codes are DFW and CLT.

ASSISTANT: Please wait a minute. Carol, there are no flights available at this moment.

USER: That's ok, thank you.

ASSISTANT: Thank you for contacting us.