public function renderResultsList()
        {

            $res = array();
            $query = new DbQuery();
            $query->select('*');
            $query->from('registform', 'r');
            $query->leftJoin('registform_lang', 'rl', '(rl.id_reg = r.id_reg AND rl.id_lang = '.$this->context->language->id.')');
$res = DB::getInstance()->executeS($query);

$this->_select = '
                cus.`id_customer`, cus.`firstname`, cus.`lastname`, cus.`email`, cus.`date_add`' ;
            $this->_join = '
                LEFT JOIN `' . _DB_PREFIX_ . 'customer` cus ON (a.`id_user` = cus.`id_customer`)';

            foreach($res as $r) {
                $this->_select .= ', '' `field_'.$r['id_reg'].'`';
            }



            $this->_orderBy = 'id_user';
            $this->_orderWay = 'ASC';
            $this->toolbar_btn      = array();
            $this->show_toolbar     = false;
            $this->_defaultOrderWay = 'asc';
            $this->lang             = false;
            $this->position_identifier = 'id_reg';
            $this->list_simple_header  = true;
            $this->_default_pagination = 100;
            $this->_group = 'GROUP BY a.`id_user`';

            $this->fields_list = array(
                'id_customer' => array(
                    'title' => $this->l('ID'),
                    'width' => 'auto',
                    'align' => 'center'
                ),
                'firstname' => array(
                    'title' => $this->l('First name'),
                    'width' => 'auto',
                    'align' => 'center'
                ),
                'lastname' => array(
                    'title' => $this->l('Last name'),
                    'width' => 'auto',
                    'align' => 'center'
                ),
                'email' => array(
                    'title' => $this->l('Email'),
                    'width' => 'auto',
                    'align' => 'center'
                ),
                'date_add' => array(
                    'title' => $this->l('Date add'),
                    'width' => 'auto',
                    'align' => 'center'
                )
            );


            foreach($res as $r){
                $this->fields_list['field_'.$r['id_reg']] = array('title' => $r['label'], 'width' => 'auto', 'align' => 'center', 'callback' => 'getResults');
            }
$this->tpl_list_vars['title'] = $this->l('Results');

            return parent::renderList();
        }

public function getResults($currentCellValue, $fullRow)
{
return $fullRow['reg_value'];
}