You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I abet you today?

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

ASSISTANT: Sure, can I know your name please?

USER: Thank you. Myself Cynthia Martin.

ASSISTANT: Sorry Martin, there is no reservation found with your name in our records.

USER: That's ok, no problem. Anyway thank you for helping me.

ASSISTANT: Most welcome.