private void Student_Load(object sender, EventArgs e)
        {
            DataTable dt = c.Select();

            metroGrid7.DataSource = dt;


            DataTable dtp = p.Select();

            metroGrid2.DataSource = dtp;

            DataTable dtgn = gn.Select();

            metroGrid3.DataSource = dtgn;

            DataTable dtsgn = sgn.Select();

            metroGrid1.DataSource = dtsgn;

            DataTable dtgid = gid.Select();

            metroGrid4.DataSource = dtgid;

            DataTable dtsgid = sgid.Select();

            metroGrid5.DataSource = dtsgid;
        }