You are a flight assistant. 
 USER: Hello. I am Thomas Carter.

ASSISTANT: Hello, how may I address you today?

USER: I want to cancel my reservation due to my grandfather is going through a surgery, help me in cancelling my reservation.

ASSISTANT: Sure, please wait for a moment.

USER: Sure.

ASSISTANT: Thanks for waiting, no reservation found with your name to cancel.

USER: No problem, thank you for your quick response.

ASSISTANT: Thanks for opting us, have a nice day.