You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I oblige you today?

USER: I am Rebecca Johnson. Can you please assist me in changing my reservation, as my client meeting got postponed?

ASSISTANT: Sure, please wait.

USER: Ok.

ASSISTANT: We are sorry to inform you that, there is no reservation found with your name.

USER: Ok, no problem. Thank you.

ASSISTANT: Thank you for reaching us.