You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I support you?

USER: I am Nicholas Taylor. I want to change my reservation due to sudden prepone of my exam, can you change my reservation?

ASSISTANT: Sure, please wait for a while.

USER: Sure.

ASSISTANT: Sorry, there is no reservation found on your name.

USER: Ok, thank you for informing me.

ASSISTANT: Thank you for availing us.