private void btUpdateComb_Click(object sender, EventArgs e)
        {
            DataBaseProcedure procedure = new DataBaseProcedure();

            procedure.spCombination_Update(Convert.ToInt32(
                                               dgvCombination.CurrentRow.Cells[0].Value.ToString()),
                                           Convert.ToInt32(ltbPosts.SelectedValue.ToString()),
                                           ltbEmployee.SelectedValue.ToString());
        }