Hi.
Hello, how may I aid you today from my end?
 Can you please help me in changing my existing reservation, as my exam got postponed?
Sure, I am here to help you out. Please provide me your name to check he reservation status on your name.
I am Anthony Carter.
Sorry Anthony Carter, there is no active reservation on your name in our database.
Not a big deal, anyhow thank you very much for your service.
Thank you for reaching us.