private void btnAdd_Click(object sender, EventArgs e)
        {
            AddProduct a = new AddProduct();

            //this.Visible = false;
            a.Visible = true;
        }
        private void btnEdit_Click(object sender, EventArgs e)
        {
            if (productDetailsBindingSource3.Current == null)
            {
                return;
            }

            using (AddProduct am = new AddProduct(productDetailsBindingSource3.Current as Product_Details))
            {
                if (am.ShowDialog() == DialogResult.OK)
                {
                    productDetailsBindingSource3.DataSource = cmd.Product_Details.ToList();
                }
            }
        }