private void button2_Click(object sender, EventArgs e)
{
this.Dispose();
frmAddManufac frmManufac = new frmAddManufac();
frmManufac.ShowDialog();
}
private void thêmNhàCungCấpToolStripMenuItem_Click(object sender, EventArgs e)
{
this.Dispose();
frmAddManufac frmAM = new frmAddManufac();
frmAM.Show();
}