You are a flight assistant. 
 USER: Hello. Donald Evans here.

ASSISTANT: Hello, how may I assist you?

USER: I want your help in cancellation of my ticket, as our plan has changed.

ASSISTANT: Sure, let me check the previous reservation.

USER: Ok.

ASSISTANT: Sorry Evans, there is no reservation found.

USER: That's not a problem.

ASSISTANT: Thank you for reaching us.

USER: Thank you for searching.