Hi.
user
Hello. How may I help you?
assistant
Due to some entrepreneurship meeting, I am going to change my existing reservation. Can you help me?
user
 If you can help me with your name, I can check with the availability of your reservation.
assistant
Benjamin Adams here.
user
 I am very sorry to inform you that there is no reservation found under your name in our database.
assistant
No problem, thanks for the information.
user
Thank you for choosing us.
assistant