function pv2(menu){
var URL = menu.submenu.options[menu.submenu.selectedIndex].value;
window.parent.location.href=(URL);
}

<!--
document.write('<table border="0" width="100%" cellspacing="0" cellpadding="0">');
document.write('<TBODY><tr><td align="center" vAlign="middle" width="100%"><form name="menu">');
document.write('<p align="center"><font face="courier" size="1" color="red">');
document.write('<select name="submenu" onchange="pv2(menu)" size="1">');
document.write('<option selected value="0">- Menu rápido -</option>');
document.write('<option value="index.php">Inicio</option>');
document.write('<option value="javascript:void(null)">-- Rutas --</option>');
document.write('<option value="Pais_Vasco.php">Pais Vasco</option>');
document.write('<option value="Pirineos.php">Pirineos</option>');
document.write('<option value="Picos_Europa.php">Picos de Europa</option>');
document.write('<option value="javascript:void(null)">-Y además-</option>');
document.write('<option value="modules.php?name=Topics">Otras Zonas</option>');
document.write('<option value="modules.php?name=Stories_Archive">Hemeroteca</option>');
document.write('<option value="javascript:void(null)">-Otras Secciones-</option>');
document.write('<option value="modules.php?name=My_eGallery">Gallery</option>');
document.write('<option value="javascript:void(null)">-Información-</option>');
document.write('<option value="Refugios.php">Refugios</option>');
document.write('<option value="Clubes.php">Clubes</option>');
document.write('<option value="Federacion.php">¿Federarse?</option>');
document.write('<option value="Senderos.php">Senderos</option>');
document.write('<option value="Noticias.php">Noticias</option>');
document.write('<option value="modules.php?name=Web_Links">Links nuevos</option>');
document.write('<option value="Enlaceframe.html">Links antiguos</option>');
document.write('<option value="El_Tiempo.php">El tiempo</option>');
document.write('<option value="javascript:void(null)">-Interactividad-</option>');
document.write('<option value="modules.php?name=Forums">Foros</option>');
document.write('<option value="modules.php?name=guestbook">Libro de Visitas</option>');
document.write('</select></font></form></td>');
document.write('</font></center></div></tr></TBODY></table>');
document.write('</div>');

// End -->