You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I assist you?

USER: Charles Gonzalez here, can you change my existing reservation to new dates?

ASSISTANT: Ok, please wait a moment.

USER: Sure, get back with my status of reservation.

ASSISTANT: Sorry Charles, no reservation found with your name.

USER: It's ok, may be it was not done properly while booking itself. Anyway, thanks for checking.

ASSISTANT: Ok. Thank you for choosing us.

USER: Welcome, have a good day.