public function executeAsignarvacante(sfWebRequest $request)
{
    $anio = $this->getRequestParameter('anio');
    $mes  = $this->getRequestParameter('mes');

    $valmes = TvacantesPeer::getMes($mes);
    $val = TvacantesPeer::getAreas($anio, $valmes);

    $this->getResponse()->setContentType('application/json');

    return $this->renderText(json_encode($val));
}