You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I support you today?

USER:  I am Donna Adams want to cancel my reservation due to prepone of my brother wedding.

ASSISTANT: Ok, I will help you with that. Please wait for a moment, while I search for the reservation.

USER: Ok.

ASSISTANT: Thank you for waiting, sorry to inform you there is no any reservation found on your name.

USER: Thank you for your service.

ASSISTANT: Thank you for visiting us, have a nice day.