You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I assist you?

USER: I want to change an existing reservation, so please help me in changing the reservation.

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

USER: Thank you. Stephen Rodriguez here.

ASSISTANT: Please hold on a moment.

USER: Ok.

ASSISTANT: Stephen Rodriguez, no reservation has been found on your name in our database.

USER: Not an issue. Thank you.

ASSISTANT: Thank you for reaching us.