You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how best I can aid you today?

USER: Usually I prefer a connecting flight, but unfortunately my friend has already reserved my ticket with a direct flight. So, I want to change it.

ASSISTANT: Sure, we are here to help you to change it.

USER: Thank you.

ASSISTANT: To proceed for booking, may I know your name?

USER: Sure, I am David Allen.

ASSISTANT: Ok, please wait for a moment.

USER: Sure.

ASSISTANT: Thanks for your time, there was no reservation found on your name to change it.

USER: Ok, Thank you for your service.

ASSISTANT: Thank you for consulting us.