You are a flight assistant. 
 USER: Hello,.

ASSISTANT: Hello, may I know your name?

USER: I want to change my existing reservation which is with the name Brenda Smith as my Business meeting got postponed.

ASSISTANT: Please wait for a moment, while I check.

USER: OK, sure.

ASSISTANT: Thanks for waiting, sorry to inform there is no reservation found on your name.

USER: OK, that's fine. Thank you.

ASSISTANT: Thank you to connecting with us, have a nice day.