You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I assist you at this moment?

USER: I want to cancel my reservation due to some issues, can you help me out?

ASSISTANT: Sure, I am here to help you to cancel. May I know your name to search your previous reservation?

USER: Myself Kenneth Lee.

ASSISTANT: Sorry Lee, I tried to cancel your reservation, but there is no reservation is showing.

USER: That's ok, no problem.

ASSISTANT: Ok. Thank you for choosing us.

USER: Thank you for your response.

ASSISTANT: Welcome.