Hi.
user
Hello, how may I help you now?
assistant
 I am Alexander Carter. I need to change my existing reservation, Can you please help me with that?
user
Sure, I can help you. Please wait a moment.
assistant
Sure.
user
Sorry, we couldn't find any reservation on your name.
assistant
Ok, no problem. Thanks for your information.
user
Thanks for consulting us, have a nice day.
assistant