Hello,. I am James Lee.
user
Hello, how may I be of your service?
assistant
I want to change my existing reservation, please help me out.
user
Sure, please wait a minute. I will check and revert to you.
assistant
Ok.
user
Thank you for being patient. Unfortunately there is no reservation found according to your  name.
assistant
No issues, thank you.
user
Thank you for being with us.
assistant