STEPBACK
if (st_check_density_or_wfm(un->un_dev, 1, B_READ, STEPBACK)) {
if (st_check_density_or_wfm(un->un_dev, 1, B_READ, STEPBACK)) {
if (st_check_density_or_wfm(un->un_dev, 1, 0, STEPBACK)) {
if (st_check_density_or_wfm(un->un_dev, 1, 0, STEPBACK)) {
if (st_check_density_or_wfm(un->un_dev, 1, 0, STEPBACK)) {
if (stepflag == STEPBACK) {