Hello.
Hello. How can I assist you today?
Actually my sister's engagement got postponed so that I want to change an existing reservation, can you help me?
Sure, I will help you that.
Ok, sure.
Please give me a minute, I will come back with your details. May I know your travelling dates?
Sure, I am Rebecca Williams. And I want to travel on 07/28 to 07/30.
I need your airport codes to proceed the booking?
My changed airport codes are DFW from LAS.
Wait for a moment, I will check  it.
Make sure that the connection limit is 1. Ok.
I did not find any flight with your details.
Ok, no problem. Thank you for your information.
Thank you for your reaching us.