You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I help you?

USER: I want to change my reservation, because my friends are unable to come on our planned date.  So will you help me with changing the ticket?

ASSISTANT: Sure. May I have your name?

USER: My name is Mark White.

ASSISTANT: Please hold on for a moment.

USER: Ok.

ASSISTANT: Sorry Mark. I could not find any reservation on your name.

USER: It's ok, thank you for checking my reservation.

ASSISTANT: Thank you.