LTER TABLE `dle_comments`
        ADD `ns_level` INT(11) DEFAULT NULL;
ALTER TABLE `dle_comments`
        ADD `ns_right` BIGINT(20) NOT NULL DEFAULT 0;
ALTER TABLE `dle_comments`
        ADD `ns_left` BIGINT(20) NOT NULL DEFAULT 0;

$comments->query = "SELECT " . PREFIX . "_comments.id,
            post_id, " . PREFIX . "_comments.user_id, date, autor as gast_name,
                " . PREFIX . "_comments.email as gast_email, text, ip, is_register, name,ns_level, " . USERPREFIX . "_users.email, news_num, comm_num, user_group, reg_date, signature, foto, fullname, land, icq, xfields FROM " . PREFIX . "_comments
                    LEFT JOIN " . USERPREFIX . "_users ON " . PREFIX . "_comments.user_id=" . USERPREFIX . "_users.user_id
                        WHERE " . PREFIX . "_comments.post_id = '$news_id'" . $where_approve . " ORDER BY " . PREFIX . "_comments.ns_right DESC  ";

        #$sql_result = $this->db->query($this->query . " LIMIT " . $this->cstart . "," . $this->comments_per_pages);
        #Стало
        $sql_result = $this->db->query($this->query);

        //if ($update_comments) {
        //добавляем
        $_ns_id = (int) $_REQUEST['ns_parent_id'];
        if ($_ns_id)
            $update_comments = false;
            //после $comments = $db->safesql($comments);

            require_once ROOT_DIR . '/engine/classes/dbtree/db_mysql.class.php';
            require_once ROOT_DIR . '/engine/classes/dbtree/dbtree.class.php';
            $_db = new _db(DBHOST, DBUSER, DBPASS, DBNAME);
            $dbtree = new dbtree(PREFIX . '_comments', 'ns', $_db);
            if ($_ns_id) {
                $dbtree->Insert($_ns_id, array(
                    'and' => array('parent_id' => "post_id='" . $post_id . "'")
                        ), array(
                    'post_id' => $post_id,
                    'user_id' => $member_id['user_id'],
                    'date' => $time,
                    'autor' => $name,
                    'text' => $comments,
                    'ip' => $_IP,
                    'is_register' => 1,
                    'approve' => $where_approve
                ));
            } else {
                if ($is_logged)
                    $db->query("INSERT INTO " . PREFIX . "_comments
                                    (post_id, user_id, date, autor, email, text, ip, is_register, approve) values
                                    ('$post_id', '$member_id[user_id]', '$time', '$name', '$mail', '$comments', '$_IP', '1', '$where_approve')");
                else
                    $db->query("INSERT INTO " . PREFIX . "_comments (post_id, date, autor, email, text, ip, is_register, approve) values ('$post_id', '$time', '$name', '$mail', '$comments', '$_IP', '0', '$where_approve')");
            }

//            if ($is_logged)
//                $db->query("INSERT INTO " . PREFIX . "_comments
//                                    (post_id, user_id, date, autor, email, text, ip, is_register, approve) values
//                                    ('$post_id', '$member_id[user_id]', '$time', '$name', '$mail', '$comments', '$_IP', '1', '$where_approve')");
//            else
//                $db->query("INSERT INTO " . PREFIX . "_comments (post_id, date, autor, email, text, ip, is_register, approve) values ('$post_id', '$time', '$name', '$mail', '$comments', '$_IP', '0', '$where_approve')");

$comments->query = "SELECT " . PREFIX . "_comments.id, post_id, " . PREFIX . "_comments.user_id, date, autor as gast_name,
        " . PREFIX . "_comments.email as gast_email, text, ip, is_register, name,
            " . USERPREFIX . "_users.email, news_num, comm_num, user_group, reg_date, signature, foto, fullname, land, icq, xfields
                FROM " . PREFIX . "_comments LEFT JOIN " . USERPREFIX . "_users
                    ON " . PREFIX . "_comments.user_id=" . USERPREFIX . "_users.user_id
                        WHERE " . PREFIX . "_comments.post_id = '$post_id' order by id DESC LIMIT 1";

function add_answer(parent_id){
    var button = {};
    var a=document.getElementById("dle-comments-form");
    if(dle_wysiwyg=="yes"){
        document.getElementById("comments").value=$("#comments").html();
        var b="wysiwyg"
    }else b="";
    button[dle_p_send]=function(){
        ShowLoading("");
        $.post(dle_root+
            "engine/ajax/addcomments.php",{
                post_id:a.post_id.value,
                comments: $('#review').val(),
                name:a.name.value,
                mail:a.mail.value,
                editor_mode:b,
                skin:dle_skin,
                ns_parent_id: parent_id,
                allow_subscribe: '0'
            },function(b){
                if(a.sec_code)a.sec_code.value="",reload();
                HideLoading("");
                RunAjaxJS("answer-"+parent_id,b);
                b!="error"&&document.getElementById("blind-animation")&&($("html"+(!$.browser.opera?",body":"")).animate({
                    scrollTop:$("#dle-ajax-comments").offset().top-70
                },1100),setTimeout(function(){
                    $("#blind-animation").show("blind",

                    {},1500)
                },1100))
            })
        $(this).dialog("close");
    };
    $("#d-popup").remove();
    var div = $('<div id="d-popup" style="display:none"></div>'),
    frm = $('<form name="answer"><textarea id="review" rows="6" cols="" name="review" style="width:98%"></textarea></form>')
    $("body").append(div);
    $(div).append(frm)
    $("#d-popup").dialog({
        autoOpen: true,
        width: 690,
        height: 270,
        resize:false,
        buttons: button,
        open: function(){
        }
    });
}

<div class="bcomment" style="padding-left:{level}0px !important">
.............
<span class="reply"><a href="javascript:add_answer('{id}')"><b>Ответить</b></a></span>
..............
<div id="answer-{id}" style="padding-left:{level}9px !important"></div>