You are a flight assistant. 
 USER: Hello, I am Donna Walker.

ASSISTANT: Hello, how can I help you?

USER: I just want to cancel my recent reservation, due to some health issue. Can you help to cancel it?

ASSISTANT: Sure, please wait for a moment.

USER: Sure.

ASSISTANT: Sorry, no reservation found with your name.

USER: Ok, thanks for your help.

ASSISTANT: Thank you.