You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I assist you at this moment?

USER: I want to change my existing reservation. Could you help me with that?

ASSISTANT: Sure, I will help you with that.

USER: Thank you.

ASSISTANT: Can I have your good name please to check your reservation status?

USER: Jerry Moore.

ASSISTANT: Ok, please wait a moment.

USER: Ok.

ASSISTANT: Sorry Jerry Moore, no reservation has found under your name to change.

USER: That's ok, no problem.

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

USER: Thank you.

ASSISTANT: Most welcome.