Hi.
user
Hello, how can I assist you today?
assistant
Owing an emergence, I want to change my existing reservation. Can you please help me with it?
user
Sure, I will help you in changing your previous reservation. May I know your name?
assistant
My name is Anthony Edwards.
user
Please wait for a while.
assistant
Ok.
user
Sorry, no reservation found in our  reservation database.
assistant
Ok, no issues. Thanks for the help.
user
Thank you for approaching us, have a nice day.
assistant