int QSget_named_x (QSprob p, const char *colname, double *val)
/* p is an initialized QSprob, a handle to an existing LP problem  */
/* Get the solution value of the variable z.                       */

int rval;
double val;

rval = QSget_named_x (p, "z", &val);
if (rval) {
    fprintf (stderr,
             "Could not get the x-value, error code %d\n", rval);
} else {
    printf ("Solution value = %.6f\n", val);
}