A PHP Error was encountered

Severity: Notice

Message: Undefined index: 2,

Filename: web/header.php

Line Number: 35

Backtrace:

File: /home/minedition/www/www/application/views/web/header.php
Line: 35
Function: _error_handler

File: /home/minedition/www/www/application/views/web/books_detail_view.php
Line: 1
Function: view

File: /home/minedition/www/www/application/controllers/Books.php
Line: 523
Function: view

File: /home/minedition/www/www/index.php
Line: 292
Function: require_once