public function sortingLink()
    {
        $filterlist = '';

        if ($this->getParameter('filter') != null) {
            foreach ($this->getParameter('filter') as $get => $value) {
                $filterlist .= 'filter['.$get.'][]='.$value.'&';
            }
        }
        if ($this->getParameter('sort') != null) {
            $sort = $this->getParameter('sort');
        } else {
            $sort = array();
        }
        if (!empty($sort[$this->getParameter('field')])) {
            if ($sort[$this->getParameter('field')] == 'ASC') {
                return $filterlist.'sort['.$this->getParameter('field').']=DESC';
            } else {
                return $filterlist.'sort['.$this->getParameter('field').']=ASC';
            }
        }
        return $filterlist.'sort['.$this->getParameter('field').']='.$this->getParameter('order');
    }