You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I assist you?

USER: Due to health issue, I want to cancel my reservation. Can you help me out?

ASSISTANT: Sure, I will help you in cancelling. May I know your name?

USER: Sure, my name is Benjamin Davis.

ASSISTANT: Sorry Davis, there is no reservation is showing in our data base to cancel.

USER: That's ok, thank you.

ASSISTANT: Welcome. Thank you for choosing us.