You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I help you.

USER: I want to change my existing reservation, can you help me out?

ASSISTANT: Sure, we are here to help you.

USER: Thank you.

ASSISTANT: Can I know your name please to proceed further?

USER: Sure, I am Betty Smith.

ASSISTANT: Please wait for a while.

USER: Sure.

ASSISTANT: Sorry to inform you that there is no active reservation on your given name.

USER: Ok, no problem. Thank you.

ASSISTANT: Thanks for reaching us, have a nice day.