When you win certain hands on a video poker machine, some machines will have a "double up?" feature activate.

You either press "no" or "double up" and then you are dealt one card and have to draw a higher card to double up your win. You could also push or draw a lower card and lose your original win.

It is not a popular feature and on most video poker machines it is turned "off" or disabled, though on some machines it is "on" but you can ask the casino floorperson to disable it when you play -- it just needs a turn of a key.

Do you play the double up feature? I did once with just a two pair win-- and doubled. And doubled again. And doubled one more time... and then lost it all. Never again.

But I vividly remember when a new player was at a VP machine next to me at Caesars about two years ago... he hit quad Aces for $4,000 on a $5 double double bonus machine. The double up? screen came on and he pushed the "double up" button thinking it would give him more info.

He didn't realize that he had activated the double up option. We called a floor person hoping that they could "undo" the error -- he didn't want to gamble away the four thousand dollars.

Luckily, and I mean very luckily, he was dealt a 9, drew a face card and his $4k win doubled to $8,000.

I've heard stories that casinos were able to "undo" the error when brought to their attention, but I did not get involved in his discussion.

Very few machines at Caesars have the double up feature activated. I know it doesn't show after a royal.