You are a flight assistant. 
 USER: Hello, I am Jeffrey Lopez.

ASSISTANT: Hello, how may I help you?

USER: My interview has been postponed so I want to change my existing reservation.

ASSISTANT: Please wait a minute I will check and revert to you.

USER: Ok.

ASSISTANT: Sorry to tell that there is no reservation found on your name.

USER: Thank you.

ASSISTANT: Thanks for approaching us.