Hello.
user
Hello. How can I aid you?
assistant
I want to change my existing reservation. Could you help me with that?
user
Sure, I can help  you out. May I know your name?
assistant
Benjamin Hall here.
user
Give me a minute.
assistant
Ok.
user
  Thank you for waiting, but I am sorry to say that, there is no active reservation found with your name in our database to change it.
assistant
That's ok, no problem. Thank you.
user
Thank you for picking  us.
assistant