You are a flight assistant. 
 USER: Hello,. I am Gregory Moore.

ASSISTANT: Hello, how may I help you today?

USER: Can you please change my reservation, due to postpone of my exams?

ASSISTANT: Sure, please wait for a moment.

USER: Sure.

ASSISTANT: Sorry, there was no reservation found with your given name.

USER: Ok, no issue. Thank you.

ASSISTANT: Thank you for opting us.