private void ĐăngKíKhếUơc_Click(object sender, EventArgs e)
 {
     if (HoSoKheUocfrm == null || HoSoKheUocfrm.IsDisposed)
     {
         HoSoKheUocfrm           = new frmHoSoKheUoc();
         HoSoKheUocfrm.MdiParent = this;
         HoSoKheUocfrm.Show();
     }
     else
     {
         HoSoKheUocfrm.Activate();
     }
 }
        private void btnThemKU_Click(object sender, EventArgs e)
        {
            frmHoSoKheUoc HSKU = new frmHoSoKheUoc();

            HSKU.ShowDialog();
        }
        private void btnThemMaSoKU_Click(object sender, EventArgs e)
        {
            frmHoSoKheUoc hsku = new frmHoSoKheUoc();

            hsku.ShowDialog();
        }