The custom javascript option has been deprecated. Please note that if you have used custom javascript in your existing forms or create new forms by making a copy of the existing forms in Neartail, the custom javascript will continue to work without issues. Instead of using a custom script for managing inventory, I'd recommend you to use the Neartail templates to create your order form and enable the inventory option to set up available stock for your products. Neartail will keep track of product orders and automatically mark the product as sold out when the available stock becomes zero. Order form templates https://neartail.com/order-forms/index.html Enable inventory https://neartail.com/order-form/add-products-with-limited-stock.html