Добавление комментария на отдельной странице со статьей

if(isset($_POST["add"])) {
    $article_id = $_POST["article_id"];
    $comment = $_POST["comment"];
    $name  = $_POST["name"];
}

<?php
    ini_set("display_errors", 1);
    error_reporting(E_ALL);
 
    /* The Comment Class */
    class Comment {
        
        private $mysqli;
        
        private static $mycomment = null; //It's means that I can add more and more comments
        
        /* Connecting... */
        
        public function __construct() {
            $this->mysqli = new Mysqli('localhost', 'root', '', 'cms');
            $this->mysqli->query("SET NAMES 'utf8'");
        }
        
        public static function getComment() {
            if(self::$mycomment === null) self::$mycomment = new Comment();
            return self::$mycomment;
        }
        
                    /*Comment Functions*/
        public function viewComment($name, $comment)
        {
            $this->mysqli->query("SELECT `text_comment``.*.`id`,`name` FROM `articles` LEFT JOIN `text_comment`` USING (`name`) WHERE `article_id`={$page['article_id']} AND `published` ORDER BY `id` LIMIT {($pn-1)*$pp},{$pp}");
        }
        
        
        public function addComment($name, $comment) 
        {
            if($name =="") return false;
            if($comment =="") return false;
            $this->mysqli->query("UPDATE `articles` SET `name` = '$name', `text_comment` = '$comment' WHERE(`id` = '$id')");
            
        }
        /* Closing the connection */
        
        public function __destruct() {
            if($this->mysqli) $this->mysqli->close();
        }
    
    
    
    
    
    
    
    
    
    
    }
 
 
?>

public function addComment($name, $comment)
{
if($name =="") return false;
if($comment =="") return false;
$this->mysqli->query("INSERT INTO `articles` (`name`, `text_comment`) VALUES('$name', '$comment') ")