Hi.
user
Hello. How can I help you?
assistant
I want to change an existing reservation due to sudden change in my trip.
user
Ok. To change your reservation, I need your name. Can you please help with it?
assistant
 Sure, I am James White.
user
Sorry, there is no reservation found by your name.
assistant
Ok. Thank you for your response.
user
Thank you and have a nice day.
assistant