private void simpleButton8_Click(object sender, EventArgs e)
        {
            etat_tache = "ajouter";
            add_modif_taches aa = new add_modif_taches();

            aa.ShowDialog();
        }
        private void simpleButton7_Click(object sender, EventArgs e)
        {
            etat_tache = "modifier";
            int count = gridView1.DataRowCount;

            if (count != 0 && gridView1.FocusedRowHandle != DevExpress.XtraGrid.GridControl.AutoFilterRowHandle)
            {
                System.Data.DataRow row = gridView1.GetDataRow(gridView1.FocusedRowHandle);
                id_tache = Convert.ToInt32(row[0]);

                add_modif_taches aa = new add_modif_taches();
                aa.ShowDialog();
            }
        }