Hello.
user
Hello. How can I help you today?
assistant
I would like to change my existing reservation, can you help me in that?
user
Sure, I am here to help you with that, can I know your good name to proceed further?
assistant
Sure, myself Daniel Moore.
user
 I am very sorry to inform you that there is no reservation found under your name in our database.
assistant
That's ok, no problem. Thank you for the information.
user
Thank you for reaching us.
assistant