Hello, I am Barbara Brown.
user
Hello, How can I help you?
assistant
I need to change my existing reservation because my university schedules are preponed. Can you please change my reservation?
user
Sure, Wait a minute  I will check and get back to you.
assistant
Ok.
user
Sorry to tell that there is no reservation on your name.
assistant
No problem. Thanks for your information.
user
Thank you for approaching us.
assistant