You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I serve you today?

USER: I am David Brown. Can you change my existing reservation due to my destination changed.

ASSISTANT: Sure. Please, wait.

USER: Sure.

ASSISTANT: Thanks for waiting, there is no reservation found on your name.

USER: Ok, No issues. Thank you.

ASSISTANT: Thank you for availing us.