private void BtnSaleProd_Click(object sender, EventArgs e) { string nameProd = tbNameProd.Text; int number = Convert.ToInt32(tbNumProd.Text); bool ifThere = false; foreach (Product p in ProductManagment.ProductsSales) { if (p.Name == nameProd && p.Category == "SALES" && p.Stocks >= number) { ProductManagment.SellProduct(nameProd, number); managment.UPDATEprodSold(nameProd); managment.UPDATEprodStock(nameProd); MessageBox.Show("Done!"); ifThere = true; } } if (ifThere == false) { MessageBox.Show("Product not found or not enough stock!"); } DataGridViewUpdateProducts(); }