<div class="row">
        <?php
            if(isset($_GET['cat']) && !empty($_GET['cat']))
            {

                $host = "localhost";
                $db_name = "avisos";
                $username = "root";
                $password = "";
                $conn = new mysqli ($host, $username, $password, $db_name);

                if ($conn->connect_error){
                    die("connection failed: ".$conn->connect_error);
                 }

                $video_id = '';
                $id = $_GET['cat'];
                $sql = "SELECT email, nombre, telefono, descripcion, img , categoria , ai FROM tbl_public WHERE categoria=$id";
                $result = $conn->query ($sql);
                if($result->num_rows > 0)
                    {
                        while ($row = $result->fetch_assoc())
                    {
                      $video_id = $row["categoria"];
                ?>
                    <div class="col-md-4 portfolio-item">

                        <p><img   src="user_images/<?php echo $row['img']; ?>"  height="175" width="210" / ></p>
                        <h3>
                            <a href="ver_publicacion.php?ai=<?php echo $row['ai']; ?>" ><?php echo $row['nombre']; ?></a>
                        </h3>
                    <!--    <p><?php echo $row['descripcion']; ?></p> -->
                    </div>
                <?php
                    }
                ?>
                    <tr id="remove_row">
                       <td><button type="button" name="btn_more" data-vid="<?php echo $video_id; ?>" id="btn_more" class="btn btn-success form-control">More</button></td>
                    </tr>
                <?php
                    }
                    else
                    {
                ?>
                    <div class="col-xs-12">
                        <div class="alert alert-warning">
                            <span class="glyphicon glyphicon-info-sign"></span> &nbsp; NO HAY PUBLICACIONES ...
                        </div>
                    </div>
                <?php
                    }
            }
        ?>
    </div>