private void btnQlPhong_Click(object sender, EventArgs e)
{
frmQlPhongHoc ql = new frmQlPhongHoc();
ql.ShowDialog();
}
private void btnSetup_Click(object sender, EventArgs e)
{
frmQlPhongHoc fph = new frmQlPhongHoc();
fph.ShowDialog();
}