메인 이미지 여러개를 같은 위치에 시간차로 출력하고 싶습니다.

<?php
define('_INDEX_', true);
if (!defined('_GNUBOARD_')) exit; // 개별 페이지 접근 불가

if (G5_IS_MOBILE) {
    include_once(G5_THEME_MOBILE_PATH.'/index.php');
    return;
}

include_once(G5_THEME_PATH.'/head.php');

add_javascript('<script src="'.G5_THEME_JS_URL.'/unslider.min.js"></script>', 10);
?>


<!--메인배너 {-->
<div id="main_bn_box">
    <div id="main_bn">
        <ul class="bn_ul">
            <li class="bn_bg1">
                <div class="bn_wr"><a href="http://blocknara.co.kr"><img src="<?php echo G5_THEME_IMG_URL ?>/main_banner1.png" alt="Merry Christmas~" /></a></div>
            </li>
            <li class="bn_bg1">
                <div class="bn_wr"><a href="http://blocknara.co.kr"><img src="<?php echo G5_THEME_IMG_URL ?>/main_banner2.png" alt="Merry Christmas~" /></a></div>
            </li>
            <li class="bn_bg1">
                <div class="bn_wr"><a href="http://blocknara.co.kr"><img src="<?php echo G5_THEME_IMG_URL ?>/main_banner3.png" alt="Merry Christmas~" /></a></div>
            </li>
            <li class="bn_bg1">
                <div class="bn_wr"><a href="http://blocknara.co.kr"><img src="<?php echo G5_THEME_IMG_URL ?>/main_banner4.png" alt="Merry Christmas~" /></a></div>
            </li>
        </ul>
    </div>
</div>
<!--} 메인배너-->
<script>
$(function() {
    $("#main_bn").unslider({
        speed: 700,               //  The speed to animate each slide (in milliseconds)
        delay: 3000,              //  The delay between slide animations (in milliseconds)
        keys: true,               //  Enable keyboard (left, right) arrow shortcuts
        dots: true,               //  Display dot navigation
        fluid: false              //  Support responsive design. May break non-responsive designs
    });
    $('.unslider-arrow').click(function() {
        var fn = this.className.split(' ')[1];

        //  Either do unslider.data('unslider').next() or .prev() depending on the className
        unslider.data('unslider')[fn]();
        });
    });
</script>