그누보드 모바일처럼 2단메뉴를 뽑고싶습니다. 채택완료

<?php
                $menu_datas = get_menu_db(0, true);
                $gnb_zindex = 999; // gnb_1dli z-index 값 설정용
                $i = 0;
                foreach( $menu_datas as $row ){
                    if( empty($row) ) continue;
                    $add_class = (isset($row['sub']) && $row['sub']) ? 'gnb_al_li_plus' : '';
                ?>
                <li class="gnb_1dli <?php echo $add_class; ?>" style="z-index:<?php echo $gnb_zindex--; ?>">
                    <a href="<?php echo $row['me_link']; ?>" target="_<?php echo $row['me_target']; ?>" class="gnb_1da"><?php echo $row['me_name'] ?></a>
                    <?php
                    $k = 0;
                    foreach( (array) $row['sub'] as $row2 ){

                        if( empty($row2) ) continue; 

                        if($k == 0)
                            echo '<span class="bg">하위분류</span><div class="gnb_2dul"><ul class="gnb_2dul_box">'.PHP_EOL;
                    ?>
                        <li class="gnb_2dli"><a href="<?php echo $row2['me_link']; ?>" target="_<?php echo $row2['me_target']; ?>" class="gnb_2da"><?php echo $row2['me_name'] ?></a></li>
                    <?php
                    $k++;
                    }   //end foreach $row2

                    if($k > 0)
                        echo '</ul></div>'.PHP_EOL;
                    ?>
                </li>
                <?php
                $i++;
                }   //end foreach $row