$_SESSION['insert'] = "Record inserted into the database";
                        session_regenerate_id();
                        session_write_close();
                        echo '...succesfully add new book...';
                        header("Location: index.php");
                        exit();

<?php if(isset($_SESSION['insert'])){
?>
<p class="update"><?php echo $_SESSION['insert'];?></p>
<?php
}//end of isset $_SESSION['insert']
?>