You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I help you?

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

ASSISTANT: Sure, I am here to help you. May I know your name please?

USER: My name is Ryan Collins.

ASSISTANT: Ok, please stand by.

USER: Sure.

ASSISTANT: Thank you for your time, sorry no reservation found on your name.

USER: That's ok, no problem. Thank you for the information.

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