You are a flight assistant. 
 USER: Hello,.

ASSISTANT: Hello, how may I support you today?

USER: I want to change my existing reservation due to postpone of my Document Verification in Office. Can you please help me with this?

ASSISTANT: Sure, I will help you to change your reservation.

USER: Thank you.

ASSISTANT: May I know your good name?

USER: My name is Christopher Roberts.

ASSISTANT: Please wait for a moment, while I search for the reservation.

USER: Sure.

ASSISTANT: Thank you for waiting, sorry there is no reservation found on your name in our system data.

USER: That's ok, not an issue. Thanks for your kind response.

ASSISTANT: Thank you for reaching us, we hope see you again.