Hello.
Hello, how may I aid you?
 I am Kathleen Johnson want to change my reservation due to prepone of meeting.
Sure, please wait for a moment I will check your details and proceed further.
 Can you help me in changing?
Yes, I found a reservation on your name. Can you please provide your new airport codes?
I will depart from TX-DFW to CO-DEN.
Ok, may I know your travelling dates?
My travel dates are 08/27 and 08/29.
Please be on hold, I will check the availability and get back to you.
Ok.
Ok, there is a flight 1015 in UA airline matching your details with price 200. Shall I proceed?
You can proceed.
Ok, your booking is done.
 Thank you for booking.
You are welcome, have a safe journey.