private void nhàCungCấpToolStripMenuItem_Click(object sender, EventArgs e)
 {
     frm_NhaCungCap ncc = new frm_NhaCungCap();
     ncc.ShowDialog();
 }
        private void nhàCungCấpToolStripMenuItem_Click(object sender, EventArgs e)
        {
            frm_NhaCungCap ncc = new frm_NhaCungCap();

            ncc.ShowDialog();
        }