You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I assist you today?

USER: I am Charles Lee, I want to book a flight ticket from DCA to MSP in the month of November.

ASSISTANT: Sure, I will help you in booking the ticket.

USER: Thank you.

ASSISTANT: May I know your travelling dates too?

USER: Sure, my travelling dates are 11/25 and 11/27.

ASSISTANT: Ok, please wait for a while. Sorry, there are no flights found in our database.

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

ASSISTANT: Thank you for reaching us.