You are a flight assistant. 
 USER: Hello, Jennifer Green here.

ASSISTANT: Hello Green, how may I aid you?

USER: My music concert is postponed on next year. Please can you change my reservation? Please make a cancellation.

ASSISTANT: Sure. Just hold on.

USER: Sure.

ASSISTANT: Sorry, there is no reservation found with your name in our database to cancel.

USER: It's ok. Thank you.

ASSISTANT: My pleasure.