You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: Christopher Campbell here.

ASSISTANT: How can I aid you at this moment?

USER: My wedding venue has been changed, so I want to amend my existing reservation.

ASSISTANT: Sure, I will help you in amending your reservation.

USER: Ok.

ASSISTANT: Please allow me a moment to check for your previous reservation status.

USER: Sure.

ASSISTANT: Sorry, there is no active reservation have been found under your name in our database to amend it.

USER: No problem, thank you for the help.

ASSISTANT: Thank you for reaching us, have a great day.