ajax call to load a page on scrolling

                                    <?php

$host = "localhost"; /* Host name */
$user = "root"; /* User */
$password = ""; /* Password */
$dbname = "tutorial"; /* Database name */

$con = mysqli_connect($host, $user, $password,$dbname);

// Check connection
if (!$con) {
  die("Connection failed: " . mysqli_connect_error());
}

                                    var position = $(window).scrollTop();
var bottom = $(document).height() - $(window).height();

                                    CREATE TABLE `posts` (
  `id` int(11) NOT NULL PRIMARY KEY AUTO_INCREMENT,
  `title` varchar(100) NOT NULL,
  `description` text NOT NULL,
  `link` varchar(255) NOT NULL
) ENGINE=InnoDB DEFAULT CHARSET=latin1;

                                    <div class="container">

<?php

 include "config.php";

 // Row per page
 $rowperpage = 3;

 // counting total number of posts
 $allcount_query = "SELECT count(*) as allcount FROM posts";
 $allcount_result = mysqli_query($con,$allcount_query);
 $allcount_fetch = mysqli_fetch_array($allcount_result);
 $allcount = $allcount_fetch['allcount'];

 // select first 3 posts
 $query = "select * from posts order by id asc limit 0,$rowperpage ";
 $result = mysqli_query($con,$query);

 while($row = mysqli_fetch_array($result)){

   $id = $row['id'];
   $title = $row['title'];
   $content = $row['description'];
   $shortcontent = substr($content, 0, 160)."...";
   $link = $row['link'];
 ?>

   <div class="post" id="post_<?php echo $id; ?>">
     <h1><?php echo $title; ?></h1>
     <p>
       <?php echo $shortcontent; ?>
     </p>
     <a href="<?= $link ?>" target="_blank" class="more">More</a>
   </div>

 <?php
 }
 ?>

 <input type="hidden" id="row" value="0">
 <input type="hidden" id="all" value="<?php echo $allcount; ?>">

</div>

                                    .container{
 width: 55%;
 margin: 0 auto;
 border: 0px solid black;
 padding: 10px 0px;
}

/* post */
.post{
 width: 97%;
 min-height: 200px;
 padding: 5px;
 border: 1px solid gray;
 margin-bottom: 15px;
}

.post h1{
 letter-spacing: 1px;
 font-weight: normal;
 font-family: sans-serif;
}


.post p{
 letter-spacing: 1px;
 text-overflow: ellipsis;
 line-height: 25px;
}

/* more link */
.more{
 color: blue;
 text-decoration: none;
 letter-spacing: 1px;
 font-size: 16px;
}

                                    <?php

// configuration
include 'config.php';

$row = $_POST['row'];
$rowperpage = 3;

// selecting posts
$query = 'SELECT * FROM posts limit '.$row.','.$rowperpage;

$result = mysqli_query($con,$query);

$html = '';

while($row = mysqli_fetch_array($result)){
  $id = $row['id'];
  $title = $row['title'];
  $content = $row['description'];
  $shortcontent = substr($content, 0, 160)."...";
  $link = $row['link'];
  // Creating HTML structure
  $html .= '<div id="post_'.$id.'" class="post">';
  $html .= '<h1>'.$title.'</h1>';
  $html .= '<p>'.$shortcontent.'</p>';
  $html .= '<a href="'.$link.'" target="_blank" class="more">More</a>';
  $html .= '</div>';

}

echo $html;