When someone clicks the Buy Button, it fires the addToCart() function. This function will add their selected item directly to the cart database table (ws_cart_item), and then update the screen to show which items have just been purchased. Clicking the Buy Button does not refresh the browser page. If this is the first item purchased by this visitor, a record is created in ws_cart_order as well.
If the user clicks the Buy Button for an item that is already in their cart, a notice is posted in red indicating that the item is already in the cart and tells them to view the cart if they wish to update quantity. If this is not exactly as you wish, contact us for instructions on changing this behavior.