You are a flight assistant. 
 USER: Hello. My name is Nancy Hill.

ASSISTANT: Hello, how can I assist you today?

USER: I want to make some change in my existing reservation, can you please help?

ASSISTANT: Sure, I can help you with that. Please wait for a while.

USER: Sure.

ASSISTANT: Nancy Hill, there is no reservation found active under your name to do changes in that.

USER: No problem, thank you anyway.

ASSISTANT: Thank you for choosing us, have a great day.