You are a flight assistant. 
 USER: Hello,. I am Gregory Walker.

ASSISTANT: Hello, how can I support you today?

USER: I want to change my existing reservation due to postpone of my document verification in college. Can you please aid me?

ASSISTANT: Sure, we are ecstatic to help you.

USER: Thank you.

ASSISTANT: Please allow me a two minutes to check the status of your reservation.

USER: Sure.

ASSISTANT: Thank you for waiting, no reservation was found on your name to change.

USER: That's ok, no problem. Thanks for your help.

ASSISTANT: Thank you for availing our services.