You are a flight assistant. 
 USER: Hello. I am Janet White.

ASSISTANT: Hello, how can I assist you Mr. Janet White?

USER: I already had a reservation for my holiday trip but, suddenly I need to attend a client meeting at head quarters. So I need to change my reservation.

ASSISTANT: Please wait a moment, I will check.

USER: Sure.

ASSISTANT: Thank you for waiting. Sorry, there is no reservation been found on your name to change.

USER: No problem, thank you for the information.

ASSISTANT: Thank you for choosing our agency.