You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How may I assist you now?

USER: Could you please change my existing reservation due to postpone of my exams?

ASSISTANT: Sure, I am glad to help you with that. Can I know your name to check your previous reservation?

USER: My name is Laura Taylor.

ASSISTANT: Please wait a moment.

USER: Sure.

ASSISTANT: We regret to inform you that, there is no reservation found your name in our records.

USER: Not a problem, thank you for checking.

ASSISTANT: Thank you for approaching us, have a great day.