How do you do the card trick where you spell out the persons card that they chose?

If you are referring to the traditional trick, you would pick a card from the deck, then, when you are not looking, they turn flip the deck upside down (if the back is 1 side up but the front is correct up or down) then, when they open their eyes, they look for the one that is upside down and that's your card. If you are referring to a game on a website where it makes the card disappear, the ones they show you at the end are not even any of the ones shown in the beginning.