You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I assist you?

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

ASSISTANT: Yes, I can help you. Sorry to inform you that there is no reservation found on your name.

USER: Ok, no problem.

ASSISTANT: Thank you for contacting us.

USER: Thank you for your time.