You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, How can I help you?

USER: Due to some health problems, I am unable to travel the trip. Can you please cancel my flight ticket booking?

ASSISTANT: Sure, May I know your name?

USER: Thank you and my name is Charles Carter.

ASSISTANT: Please wait a second.

USER: Sure.

ASSISTANT: Your ticket has been cancelled.

USER: Thank you for your immediate help in ticket cancellation.

ASSISTANT: Thank you for opting us.

USER: Welcome.