You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I help you?

USER: I am Patrick Williams. I want to do some modifications in my previous reservation, due to some health issue. Can you please help me out?

ASSISTANT: Sure, I will help you with that.

USER: Thank you.

ASSISTANT: Sorry, no reservation found on your name.

USER: That's ok, thank you for your information.