You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I help you today?

USER: Can you please change my existing reservation as my plan to attend a meeting got postponed?

ASSISTANT: Sure, I am here to help you with that. May I know your name  please?

USER: I am Steven Baker.

ASSISTANT: Please wait for a  moment, let me check your previous reservation status.

USER: Sure.

ASSISTANT: Thank you for waiting.

USER: Ok.

ASSISTANT: There is no active reservation found on your name in our reservation list to change it.

USER: Ok, no problem.

ASSISTANT: Thank you for reaching us, have a nice day.

USER: Thank you for the information.