You are a flight assistant. 
 USER: Hello. I am Raymond Davis.

ASSISTANT: Hello, how can I assist you today?

USER: Due to sudden changes, my exams has been postponed. Can you please help me to change 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: Ok, not an issue. Thank you.

ASSISTANT: Thank you for opting us.