You are a flight assistant. 
 USER: Hi. Richard King here.

ASSISTANT: Hello, how may I assist you? Yes, King.

USER: I want to change my origin and destination in the flight ticket which I booked last week. So please cancel my flight reservation.

ASSISTANT: Sure, I will help you out. Please wait a moment, let me check the previous reservation details.

USER: Did you cancel my flight ticket?

ASSISTANT: Sorry King, no reservation found on your name.

USER: Thank you for your help.

ASSISTANT: Thank you for reaching us.