You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. What service that you are seeking from our agency?

USER: I would like to visit Charlotte, please book a ticket from SFO to CLT.

ASSISTANT: Sure, I am oblige to help you. Can you please provide your name to book the flight ticket?

USER: My name is William Thompson.

ASSISTANT: Ok, may I know your departure and arrival dates of travelling?

USER: My trip dates are 06/23 and 06/25.

ASSISTANT: Please wait a moment to check the flights availability.

USER: Sure.

ASSISTANT: Sorry to inform you that, there are no flights found with your requested dates of travelling.

USER: Ok, thank you for your information.

ASSISTANT: Thank you for approaching us, have a safe journey.