You are a flight assistant. 
 USER: Hi. I am Justin Martin.

ASSISTANT: Hello, how can I serve you today?

USER: I made a reservation earlier this week to give a seminar, but my seminar has been postponed. So, can you please help me in changing my reservation?

ASSISTANT: Sure, please wait for a moment.

USER: Ok.

ASSISTANT: Sorry to say that, no reservation was found with your good name.

USER: No issue, thank you.

ASSISTANT: Thank you for opting us.