You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How may I assist you now?

USER: Could you please cancel my recent reservation due to my health issue?

ASSISTANT: Sure, may I know your name to check please?

USER: My name is Brian Walker.

ASSISTANT: I am sorry to say, there is no flight reservation by your name.

USER: Not a problem, thank you for checking.

ASSISTANT: Thank you for choosing us. Have a nice day.