You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello.

USER: I am Gary Turner.

ASSISTANT: How may I help you out?

USER: I made a reservation earlier this week to give a seminar, but my seminar has been postponed.

ASSISTANT: Ok.

USER: Can you help me in change an existing reservation?

ASSISTANT: Sure, please give me a minute.

USER: Ok.

ASSISTANT: Thanks for your time. Sorry to inform you that no reservation was found on your name to proceed further.

USER: Ok, not an issue. Thank you.

ASSISTANT: Thank you for choosing us, Have a nice day.