You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, what can I do for you?

USER: I am Justin Wilson. I need to change my existing reservation, can you help me in doing that?

ASSISTANT: Sure, please wait while I fetch your current reservation.

USER: Sure, take your time.

ASSISTANT: I don't see any reservation on your name in our system to change.

USER: Ok, no problem. Thank you for the information.

ASSISTANT: Thank you.