A PHP Error was encountered

Severity: Notice

Message: Undefined index: HTTP_REFERER

Filename: views/v_bookview.php

Line Number: 3

Backtrace:

File: /var/www/html/rass.ndsi/application/views/v_bookview.php
Line: 3
Function: _error_handler

File: /var/www/html/rass.ndsi/application/controllers/Bookshell.php
Line: 232
Function: view

File: /var/www/html/rass.ndsi/index.php
Line: 315
Function: require_once