private void Submenu_logout_Click(object sender, EventArgs e)
        {
            menu_tabel.Enabled       = false;
            menu_labTumbuhan.Enabled = false;
            Submenu_logout.Enabled   = false;
            Submenu_login.Enabled    = true;
            menu_laporan.Enabled     = false;
            mdiobj = this;

            GUI.f_login login = new GUI.f_login();
            login.ShowDialog();
        }
 private void Submenu_login_Click(object sender, EventArgs e)
 {
     GUI.f_login login = new GUI.f_login();
     login.ShowDialog();
 }