You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I aid you today?

USER: My board meeting has been postponed, I want to change my existing reservation.

ASSISTANT: Ok. May I know your good name please?

USER: Sure, I am Donna Campbell.

ASSISTANT: Ok, please wait for a moment.

USER: Sure.

ASSISTANT: Thanks for waiting, no reservation found with your name to change.

USER: Ok. Thank you for your help.

ASSISTANT: Thanks for opting us.