You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I help you right now?

USER: Can you please help me in changing my existing reservation?

ASSISTANT: Sure, I am glad to help you with that.

USER: Thank you.

ASSISTANT: Please provide your name to check your previous reservation.

USER: My previous reservation has done with the name Brandon Wilson.

ASSISTANT: Please be on hold.

USER: Sure.

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

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

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