private void button6_Click(object sender, EventArgs e)
{
BanDoi m = new BanDoi();
this.Hide();
m.ShowDialog();
this.Show();
}
private void BànĐợiToolStripMenuItem_Click(object sender, EventArgs e)
{
//this.Hide();
BanDoi bd = new BanDoi();
bd.ShowDialog();
this.Show();
}