You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I assist you now?

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

ASSISTANT: Sure, I will help you with that. Can I have your  good name  please to check your reservation status?

USER: Virginia Gonzalez.

ASSISTANT: Ok,  please wait a  moment.

USER: Ok.

ASSISTANT: Sorry Virginia Gonzalez, no reservation has found under your name to change.

USER: That's ok, no problem. Thank you.

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