You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I help you now?

USER: I am Mark Scott.

ASSISTANT: Ok.

USER: I am planning to change my existing reservation, due to some work. Can you please change my reservation?

ASSISTANT: Sure, I will change with that. Please wait for a while. Sorry Scott, there is no reservation found on your name.

USER: That's fine.

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

USER: Thank you for helping me out.

ASSISTANT: You are welcome.