You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I oblige you today?

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

ASSISTANT: Sure, please share your good name?

USER: Myself John Jackson.

ASSISTANT: Please hold a moment.

USER: Ok.

ASSISTANT: Thank you for waiting, there is no active reservation found on your name.

USER: Ok, no problem. Thank you.

ASSISTANT: Thank you.