We've been moving the store from xcart to zencart.

In xcart, when we added options to a product, we also had a place to add a piece of javascript that looked for Please Choose: in the list of options ... and if that was still selected, then the product couldn't be added to the cart and there would be a small popup message stating that all options needed to be selected in order for the product to be added to the cart.

By doing so, it reduces the need for the client to call the customer and ask what size or color or whatever they wanted since they didn't select the option(s) upon checkout.

You can see that in action here:
http://www.theironhorseman.com/motor...cat=192&page=1


Now, I thought I saw somewhere in zencart that there is something similar ... perhaps built in? Am I just missing the obvious?