You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, what sort of help are you seeking from us?

USER: I want to change my existing reservation due to postpone of exams. Can you help me in that?

ASSISTANT: Sure, I can change your reservation right now. Before that I need to know your good name please?

USER: Myself Nicholas Green.

ASSISTANT: Ok, please wait for a couple of minutes.

USER: Sure.

ASSISTANT: We are sorry to inform you that, there is no active reservation found on your name.

USER: Ok, not an issue. Thank you for your information.

ASSISTANT: Thanks for consulting us, wish you a great day.