product_head.php

<?php 
session_start();
require_once("config.php");
?>
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
  <meta name="viewport" content="width=device-width, initial-scale=1">
    <link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.6/css/bootstrap.min.css"/>
    <link rel="stylesheet" href="https://cdnjs.cloudflare.com/ajax/libs/bootstrap-validator/0.5.3/css/bootstrapValidator.css"/>
    <script type="text/javascript" src="https://code.jquery.com/jquery-1.10.2.min.js"></script>
    <script src="http://maxcdn.bootstrapcdn.com/bootstrap/3.3.6/js/bootstrap.min.js"></script>
    <script src="https://getbootstrap.com/examples/offcanvas/offcanvas.js"></script>
    <link href="single.css" rel="stylesheet">
</head>
<?php include("navigation.php"); ?>
	<div class="container">
		<div class="row">