如何在magento的管理面板上的产品列表网格中为属性添加新列及其数据

I have added a new attribute 'productcategory' with three options for add product module to select product category and store in magento db but how to display productcategory column and data accordingly in product list grid.to add column and its data my code on I have added a new attribute 'productcategory'