Hello.
Hello. How can I aid you today?
Due to some emergency, I need to change my existing reservation. Can  you help me with that?
Sure, I will help you with that changing reservation. May I know your name please?
I am Dennis Hall.
Please wait for a moment, let me check your previous reservation status.
Sure.
Thank you for waiting.
Ok.
There is no reservation found on your name in our reservation list to change it.
It's ok, not an issue. Thank you for the information.
Thank you for reaching us, have a great day.