You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I help you?

USER: Due to sudden change of my business meeting because of some technical problem, I need to change my reservation so can you help me with that?

ASSISTANT: Sure, I am happy to help you. May I know your good name?

USER: I am Stephen Hill.

ASSISTANT: Sorry, there is no active reservation on your name in our records.

USER: No problem, thanks for the information.

ASSISTANT: Thank you for choosing us.