protected void OnDDListSelectionChanged_Click(object sender, EventArgs e)
        {
            ProductController productController = new ProductController();
            CategoryController categoryController = new CategoryController();

            string category = ((DropDownList)sender).SelectedItem.Text;
            dgProducts.DataSourceID = null;

            if (!string.IsNullOrEmpty(category))
            {
                dgProducts.DataSource = productController.SelectByCategoryId(
                                        categoryController.GetIdByName(category));
            }

            dgProducts.DataBind();
        }
 protected void LinkButton_Command(object sender, CommandEventArgs e)
 {
     switch (e.CommandName)
     {
         case "New":
             {
                 Server.Transfer("AddCategoryPage.aspx");
             } break;
         case "Edit":
             {
                 Session["categoryID"] = e.CommandArgument;
                 Server.Transfer("AddCategoryPage.aspx");
             } break;
         case "Delete":
             {
                 CategoryController categoryController = new CategoryController();
                 int id = Convert.ToInt32(e.CommandArgument);
                 categoryController.RemoveCategory(id);
                 Server.Transfer("ChocolateManagement.aspx");
             } break;
     }
 }