You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I aid you?

USER: Due to health issues, I want to change my existing reservation.

ASSISTANT: Ok, I can help you with that. May I know your good name please?

USER: My name is Alexander Phillips.

ASSISTANT: Please wait for a while.

USER: Sure.

ASSISTANT: Alexander Phillips, there is no active reservation found under your name to do modifications in that.

USER: Not an issue, thank you.

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