Shopping Cart Creator puts complete control over inventory in the hands of the store owner. This gives you the responsibility for keeping track of the number of your available products. If your inventory is depleted, or if you simply don't wish to display a product, select the Don't Publish option for that product, and then save and reupload your cart.
For more inventory management options, check out Shopping Cart Creator Pro. The program comes with a built-in inventory tracking tool. To learn how to use it, check out this article: How to Manage Inventory.