public void DeleteInventoryHistoryByID(inventory_history_info inven_hisinfo)
        {
            try
            {
                using (RMSDataContext db = new RMSDataContext())
                {
                    var obj = (from inven_his in db.inventory_histories
                               where inven_his.InventoryID == inven_hisinfo.InventoryID
                               select inven_his).First();

                    db.inventory_histories.DeleteOnSubmit(obj);
                    db.SubmitChanges();
                }
            }
            catch (Exception ex)
            {
                inventory_history i = new inventory_history();
            }
        }
        public void UpdateInventoryHistoryByID(inventory_history_info inven_hisinfo)
        {
            try
            {
                using (RMSDataContext db = new RMSDataContext())
                {
                    var obj = (from invenHis in db.inventory_histories
                               where invenHis.InventoryID == inven_hisinfo.InventoryID
                               select invenHis).First();
                    obj.ProductID        = inven_hisinfo.ProductID;
                    obj.Product_quantity = inven_hisinfo.Product_quantity;

                    db.SubmitChanges();
                }
            }
            catch (Exception ex)
            {
                inventory_history invenHis = new inventory_history();
            }
        }
        public void InsertInventoryHistory(inventory_history_info invenHis)
        {
            try
            {
                using (RMSDataContext db = new RMSDataContext())
                {
                    inventory_history tbl = new inventory_history();
                    tbl.ProductID        = invenHis.ProductID;
                    tbl.Product_quantity = invenHis.Product_quantity;
                    //tbl.Inserted_date = DateTime.Now;

                    db.inventory_histories.InsertOnSubmit(tbl);
                    db.SubmitChanges();
                }
            }
            catch (Exception ex)
            {
                inventory_history inven = new inventory_history();
            }
        }