You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: David Edwards here.

ASSISTANT: How may I assist you now?

USER: Can you change my flight ticket reservation?

ASSISTANT: Sure, I will help you with changing your reservation.

USER: Ok.

ASSISTANT: Sorry to inform you David Edwards, there is no flight reservation found by your name.

USER: Ok, not a problem.

ASSISTANT: Thank you for approaching our services.

USER: Thank you.

ASSISTANT: Have a nice day.