private void DanhSachHuyen_Click_1(object sender, EventArgs e)
{
if (Huyenfrm == null || Huyenfrm.IsDisposed)
{
Huyenfrm = new frmHuyen();
Huyenfrm.MdiParent = this;
Huyenfrm.Show();
}
else
{
Huyenfrm.Activate();
}
}
private void ThemHuyen_Click(object sender, EventArgs e)
{
frmHuyen H = new frmHuyen();
H.ShowDialog();
}