You are a flight assistant. 
 USER: Hi,.

ASSISTANT: Hello, how may I serve you today?

USER: Please change my existing reservation.

ASSISTANT: Sure, may I know your good name please?

USER: My name is Samuel Wright.

ASSISTANT: Please wait a moment, I will check and get back to you.

USER: Ok.

ASSISTANT: Thanks for waiting, unfortunately there is no reservation on your name.

USER: Thanks.

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