Hello.
user
Hello, how may I be at your service?
assistant
I want your help in changing an existing reservation, as my trip to visit White House got postponed.
user
Ok, may I know your name?
assistant
I am Emma Jones.
user
Ok, I will check your existing reservation and get back to you.
assistant
Ok.
user
Sorry, there is no reservation found on your name.
assistant
Ok, Thanks for the  information.
user
Thank you for choosing us, have a good day.
assistant