You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I help you?

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

ASSISTANT: Sure, may I know your name?

USER: Ok, I am Steven Hernandez here.

ASSISTANT: Sorry to say, no reservation found on your name.

USER: Ok, not a problem.

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

USER: Thank you for your valuable help.