/span>
 <span class="nv">ierr</span>     <span class="k">If</span> <span class="nv">an</span> <span class="nv">error</span> <span class="nv">occurs</span> <span class="nv">the</span> <span class="nv">program</span> <span class="nv">is</span> <span class="nv">stopped</span> <span class="k">if</span> <span class="nv">the</span> <span class="nv">optional</span>
          <span class="nv">parameter</span> <span class="nv">IERR</span> <span class="nv">is</span> <span class="nv">not</span> <span class="nv">presen