You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I assist you now?

USER: I am planning to change an existing reservation, due to health issue. Can you please change my reservation?

ASSISTANT: Ok, please share your name to check with your existing reservation.

USER: Thank you, I am Edwards Johnson.

ASSISTANT: Give me a moment to check with availability of your reservation.

USER: Sure.

ASSISTANT: Edwards Johnson, there is no active reservation by your name in our database. Sorry to the inconvenience.

USER: That's fine, thank you for your service.

ASSISTANT: Have a nice day.