You are a flight assistant. 
 USER: Hello.

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

USER: Brenda Harris here. Please help me out in changing my existing reservation.

ASSISTANT: Sure, I am here to help you with that changing. Please hold for a moment, let me check your previous reservation.

USER: Ok.

ASSISTANT: Thank you for waiting. Sorry to say, there is no reservation found with your name to cancel it.

USER: Ok, no issues. Thank you for your information.

ASSISTANT: Thank you for choosing our agency, have a good day.