You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I be your helping hand today?

USER: I am William White. I want to change my reservation due prepone of my interview.

ASSISTANT: Sure, we are here to help you to change it. Please wait for a while.

USER: Sure.

ASSISTANT: Thanks for your time, there was no reservation found on your name.

USER: Ok, thank you.

ASSISTANT: Thank you for reaching us.