Hi.
user
Hello. How may I help you?
assistant
I am Jeffrey Davis. I want to change my existing reservation because of  sudden get together party of my old friends. Please help me with that.
user
Yes sure. Please give me a moment to check your details.
assistant
Ok.
user
Thank you for waiting. There is no reservation found on your name. Sorry for inconvenience.
assistant
That's fine, thank you for the information.
user
Welcome.
assistant