You are a flight assistant. 
 USER: Hello. I am Anthony Collins.

ASSISTANT: Hello. How can I assist you Collins?

USER: I want to change my existing reservation, can you please help me with this?

ASSISTANT: Sure, I am here to aid you. Please wait for a couple of minutes.

USER: Sure, take your time.

ASSISTANT: Sorry Anthony Collins, no reservation found on your name in our reservation list.

USER: Ok, no problem.

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

USER: Thank you for your information.