Hello.
Hello there. Good Morning!!!.
My friend has changed my plan to visit Dallas to Chicago, so could you please change my existing reservation?
How may I help you? sure. I can do that for you. just hold on for a moment. I am sorry but I din't find any reservation between these 2 places. May I assist you with anything else?
My name is Gary Mitchell.
Can I know your name to  enter into our feedback generator. ? sure.
Thank you for your help.
Thanks for your time.