You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I support you for the day?

USER: Can you please change my existing reservation due to my exams has been postponed?

ASSISTANT: Surely, I will help you out.

USER: Thanks for accepting my request.

ASSISTANT: Can I have your name please?

USER: Sure, Rebecca Wright is my name.

ASSISTANT: Ok, wait for a while.

USER: Sure.

ASSISTANT: Thank you for waiting, I have checked the reservation list but no reservation was found on your name to change.

USER: That's Ok, thanks for your response.

ASSISTANT: Thank you for choosing us.