    public function addExcelAction()
    {
        $options = array(
            'class'  => 'excel',
            //'rel'    => 'external',
            'target' => null,
            'title'  => $this->_('Export the current data set to Excel'),
            //'type'   => 'application/vnd.ms-excel',
        );

        return $this->addActionButton($this->_('Excel export'), $this->get('privilege') . '.excel', 'excel', $options);
    }