private void DanhSachTinh_Click_1(object sender, EventArgs e)
{
if (Tinhfrm == null || Tinhfrm.IsDisposed)
{
Tinhfrm = new frmTinh();
Tinhfrm.MdiParent = this;
Tinhfrm.Show();
}
else
{
Tinhfrm.Activate();
}
}
private void ThemTinh_Click(object sender, EventArgs e)
{
frmTinh T = new frmTinh();
T.ShowDialog();
}
