Hello.
Hello. How can I assist you?
Actually I have planned to travel to Atlanta, but due to some reasons the travel dates has been changed, so I need to change my reservation. Can you help me out?
Sure, can I know your name for checking the details?
Sure, my existing ticket is with name Margaret Allen.
Hold on for a minute. I will be back with the details. Sorry to say Allen, I couldn't find any reservation on your  name.
It's ok, thank you for searching.
You are welcome.