You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I serve you at this moment?

USER: I would like to change my existing reservation, which is done recently. Can you please help me out?

ASSISTANT: Sure, we are here to help you.

USER: Thank you for considering my request.

ASSISTANT: May I know your name to check your reservation status?

USER: Sure, myself Rebecca Baker.

ASSISTANT: Thank you for waiting.

USER: Ok.

ASSISTANT: Sorry, there are no reservation found with your name in our records.

USER: Not a problem, anyway thank you for the information.

ASSISTANT: Thank you for choosing us with a query.  We hope to serve you again. Have a nice day.

USER: Thank you for your service.