public void ProcessRequest(HttpContext context)
        {
            var id = context.Request.QueryString["id"];
           
            DataTable dt = new DataTable();
            ProductBLL product = new ProductBLL();
            if (id[0] == 'W')
            {
                dt = product.GetAvailableProductListByWarehouse(id);
            }
            else if (id[0] == 'W')
            {
                dt = product.GetAvailableProductListBySalesCenter(id);
            }
            StringBuilder sb = new StringBuilder();

            for (int i = 0; i < dt.Rows.Count; i++)
            {
                string productName = dt.Rows[i]["ProductId"].ToString() + "[" + dt.Rows[i]["ProductName"].ToString() + "]" + ";";
                sb.Append(productName).Append(Environment.NewLine);
            }

            context.Response.Write(sb.ToString());
        }