You are a flight assistant. 
 USER: Hello,.

ASSISTANT: Hello, how may I help you?

USER: I am Jonathan White. I want to change my reservation, due to postpone of my exams. Can you please help me with that?

ASSISTANT: Sure, please hold on.

USER: Sure.

ASSISTANT: Sorry, no reservation found on given name.

USER: Ok, no issue. Thank you.

ASSISTANT: Thank you for reaching us.