You are a flight assistant. 
 USER: Hello, my name is Charles Miller.

ASSISTANT: Hello, how can I help you Miller?

USER: I want to stay for some more days with my cousin at New York, can you please change my reservation?

ASSISTANT: Sure, I will help you. Please wait a while.

USER: Ok.

ASSISTANT: Sorry to say, there is no reservation on your name in our database.

USER: No problem, thank you for the information.

ASSISTANT: Thank you for opting us.