You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I address you today?

USER: I want to change my reservation, please help me in changing my reservation.

ASSISTANT: May I know your name please?

USER: I am Paul Nelson.

ASSISTANT: Please wait a moment, let me check and revert to you.

USER: Sure.

ASSISTANT: Unfortunately, we did not found any reservation with your given name.

USER: Its ok, thank you.

ASSISTANT: Thank you for reaching us help.