You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How can I assist you today?

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

ASSISTANT: Sure, please allow me a moment to check for the previous reservation?

USER: Ok, sure.

ASSISTANT: Brian, there is no reservation found under your name.

USER: Ok, fine thank you for checking.

ASSISTANT: Thank you for reaching us, have a great day.