You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello,  how may I help you today?

USER: I want to change my reservation, can you help me with that?

ASSISTANT: Sure, I will help you with that. May I know your good name?

USER: Paul Brown here.

ASSISTANT: Please wait for a moment, while I search for your reservation.

USER: Sure.

ASSISTANT: Thank you for waiting, sorry there is no reservation found on your name in our system data to change it.

USER: No problem, thank you for the information.

ASSISTANT: Thank you for visiting us, have a nice day ahead.