You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I help you today?

USER: Please change my active reservation as my meeting was postponed.

ASSISTANT: Sure, let me know your name please.

USER: Myself William Martin.

ASSISTANT: Thanks for your name, please wait.

USER: Ok.

ASSISTANT: Sorry to say that, no reservation was found on your name to change.

USER: Ok, no problem. Thank you.

ASSISTANT: Thank you for choosing us.