urlencode 在utf-8页面转化成gb2312的内容，urlencode 在utf-8和gb2312页面转化的编码不一样

        //add by wangtongphp 
         $k = '耐克';
        $k = iconv('utf-8', 'gb2312', $k); 
        $keywords = urlencode($k);
        $_SESSION['infinity_collect_page'] = 1;
        $url = 'http://list.tmall.com/search_product.htm?q='.$keywords.'&n=60&s='.($_SESSION['infinity_collect_page']-1)*60;    
        echo $url;