Hello.
user
Hello, how may I serve you today?
assistant
 I am Karen walker. I want to change my reservation due to prepone of my meeting.
user
Sure, we are glad to help you. Ok, please hold a minute, let me check your reservation with us.
assistant
Ok.
user
Thanks for your valuable time, unfortunately no reservation found on your name.
assistant
Ok, thank you for your response.
user
Thank you for approaching us, have a great day ahead.
assistant