You are a flight assistant. 
 USER: Hello, Gregory Mitchell here.

ASSISTANT: Hello, how may I assist you?

USER: My music concert is postponed. Can you please change my reservation?

ASSISTANT: Sure, hold on for a moment please.

USER: Ok.

ASSISTANT: Sorry to say this Gregory, there are no reservation found on your name.

USER: It's ok. Thank you to inform me.

ASSISTANT: Thank you for reaching us. Have a good day.