private void alumnoToolStripMenuItem_Click(object sender, EventArgs e)
        {
            frmAltaAlumno           = new FrmAltaAlumno();
            frmAltaAlumno.MdiParent = this;
            frmAltaAlumno.Show();

            datosAlumnoToolStripMenuItem.Enabled = true;
        }
        private void alumnosToolStripMenuItem_Click(object sender, EventArgs e)
        {
            FrmAltaAlumno alumnos = new FrmAltaAlumno();

            alumnos.Show(this);
        }