private void Formularz_Load(object sender, EventArgs e)
 {
     GridFiller.FillProductsGrid(ProductsGrid);
     GridFiller.FillPricesGrid(CenyGrid);
     GridFiller.FillPriceListsGrid(CennikiGrid);
     GridFiller.FillSummaryGrid(PodsumowanieGrid);
 }
        //@@@@@@@@ TOWARY @@@@@@@@@\\

        private void AddProductBtn_Click(object sender, EventArgs e)
        {
            using (var addform = new AddEditTowarForm(null))
            {
                if (addform.ShowDialog() == DialogResult.Yes)
                {
                    GridFiller.FillProductsGrid(ProductsGrid);
                }
            }
        }
 private void EditProductBtn_Click(object sender, EventArgs e)
 {
     try
     {
         using (var addform = new AddEditTowarForm((Towary)ProductsGrid.CurrentRow.DataBoundItem))
         {
             if (addform.ShowDialog() == DialogResult.Yes)
             {
                 GridFiller.FillProductsGrid(ProductsGrid);
             }
         }
     }
     catch (NullReferenceException exception)
     {
         MessageBox.Show(exception.Message, "Błąd", MessageBoxButtons.OK);
     }
 }
        private void DeleteProductBtn_Click(object sender, EventArgs e)
        {
            try
            {
                var towarToDel = (Towary)ProductsGrid.CurrentRow.DataBoundItem;

                if (MessageBox.Show($"Jesteś pewien że chcesz usunąć towar: {towarToDel.Nazwa}", "Formularz Towarowy",
                                    MessageBoxButtons.YesNo) == DialogResult.Yes)
                {
                    new ProductBLL().DeleteProduct(towarToDel);

                    GridFiller.FillProductsGrid(ProductsGrid);
                    GridFiller.FillPricesGrid(CenyGrid);
                }
            }
            catch (NullReferenceException exception)
            {
                MessageBox.Show(exception.Message, "Błąd", MessageBoxButtons.OK);
            }
        }