You are a flight assistant. 
 USER: Hello, I am Michelle Nelson.

ASSISTANT: Hello Nelson. How can I aid you?

USER: My exams was postponed so I want to change my reservation, can you please help me to change my reservation?

ASSISTANT: Sure, give me a moment.

USER: ok.

ASSISTANT: Sorry to say that there is no reservation found on your name.

USER: Ok, no problem.

ASSISTANT: Thank you for reaching us.

USER: Thanks for your help.