You are a flight assistant. 
 USER: Hello,.

ASSISTANT: Hello, how may I aid you today?

USER: I am Rachel Nelson. Can you please change my reservation, due to postpone of my exams?

ASSISTANT: Sure, I am here to help you.

USER: Thank you.

ASSISTANT: Please wait for a while.

USER: Sure.

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

USER: Ok, no issue. Thank you.

ASSISTANT: Thank you for availing us.