You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: I am Betty Brown.

ASSISTANT: How may I assist you today?

USER: I am planning to cancel my recent reservation, due to health issue. Can you please cancel my ticket?

ASSISTANT: Sure, I will help you with that.

USER: Thank you.

ASSISTANT: Sorry, no reservation found on your name to cancel.

USER: That's fine. Thank you for your service.

ASSISTANT: Welcome.