Hello, I am Raymond Allen.
user
Hello, how may I help you?
assistant
I want to change an existing reservation.Can you please help me with new  reservation?
user
Ok, please wait a moment. I will check the details of reservation list and inform you. There is no reservation found with your name to change the reservation.
assistant
That's Ok, no issues.
user
Thanks for contacting us. Have a great day.
assistant
Thank you for your helping hand.
user