A PHP Error was encountered

Severity: Notice

Message: Undefined index: HTTP_REFERER

Filename: controllers/Gis.php

Line Number: 57

Backtrace:

File: /home/hosting_users/merrac/www/infosystem/application/controllers/Gis.php
Line: 57
Function: _error_handler

File: /home/hosting_users/merrac/www/infosystem/application/controllers/Gis.php
Line: 39
Function: lists

File: /home/hosting_users/merrac/www/infosystem/application/controllers/Gis.php
Line: 29
Function: index

File: /home/hosting_users/merrac/www/infosystem/index.php
Line: 315
Function: require_once