Is it possible to mark products out of stock once certain number of orders have been placed for a product. Eg. A product has 1000 qty but I want to make that product out of stock immediately when orders have been placed for 100 products in a week, basically I dont want customers to order more than 100 pieces in a week. I know I can set this manually but I want to keep the site on automation. I am not quite sure where to start from programming point of view.