private void btRefresh_Click(object sender, EventArgs e)
{
dgvProStock.DataSource = cntrl_sell.Load_ProductInStock();
String[] h = { "ລະຫັດສິນຄ້າ", "ຊື່ສິນຄ້າ", "ປະເພດສິນຄ້າ", "ລາຄາ", "ຈຳນວນຍັງເຫຼຶອ", "ຫົວໜ່ວຍ" };
cntrl_col.change_columnsname(dgvProStock, h);
}
