title: Is there a way to prevent invalid row range in powerbuilder
body: <p>Is there a way to prevent invalid row range in powerbuilder.</p>
  
  <pre><code>IF  dw_lista_campanias.GetSelectedRow(0) &gt; 0 AND    dw_lista_campanias.object.est_camp[dw_lista_campanias.GetRow()] = 'EO020' THEN
  </code></pre>
  
  <p>when <strong>dw_lista_campanias.object.est_camp index is 0</strong> an exception is throw. </p>
  
  <blockquote>
    <p>Invalid row range at line 193 in ue_opcion4 event of object w_os0210_mantenimiento_campanya.</p>
  </blockquote>