You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I assist you?

USER: I want to change my existing reservation due to postpone of my interview, can you please help me with that?

ASSISTANT: Sure, I am here to help you with your concern. May I know your name to check with the status?

USER: My name is Kenneth Moore.

ASSISTANT: Please wait for a moment.

USER: Sure.

ASSISTANT: Thank you for waiting. Kenneth Moore, regret to inform that there is no active reservation found in our database.

USER: No problem, thank you.

ASSISTANT: Thank you for approaching us.