You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I help you?

USER: I want to change my existing reservation due to bad health issues. Can you help me out?

ASSISTANT: Sure, I am happy to help you. May I know your good name?

USER: I am Barbara Nelson.

ASSISTANT: Sorry, there is no active reservation on your name in our records.

USER: Ok, no issues. Thank you.

ASSISTANT: Thank you for choosing us.