int QSdelete_named_column (QSprob p, const char *colname)
/* Assume p is an initialized LP problem. */
/* Delete variable z.                     */

int rval;

rval = QSdelete_named_column (p, "z");
if (rval) {
    fprintf (stderr, 
            "could not delete variable, error code %d\n", rval);
}