private void btnSaleProduct_Click(object sender, EventArgs e)
        {
            UCShowProduct product = new UCShowProduct();

            pnlContent.Controls.Clear();
            product.Dock = DockStyle.Fill;
            pnlContent.Controls.Add(product);
            product.Show();
        }
        //GunaButton button;
        private void btnProduct_Click(object sender, EventArgs e)
        {
            //foreach (var a in db.nhomSPs)
            //{
            //    button = new GunaButton();
            //    button.Height = 35;
            //    button.Text = a.tenLoai.ToString();
            //    flowLayoutPanel1.Controls.Add(button);
            //}
            panelShowSP.Controls.Clear();
            UCShowProduct uCShowProduct = new UCShowProduct();

            panelShowSP.Controls.Add(uCShowProduct);
            uCShowProduct.Show();
        }