A PHP Error was encountered

Severity: Notice

Message: Undefined index: HTTP_REFERER

Filename: controllers/Dashboard.php

Line Number: 31

Backtrace:

File: C:\inetpub\wwwroot\exam\application\web_modules\Train\controllers\Dashboard.php
Line: 31
Function: _error_handler

File: C:\inetpub\wwwroot\exam\index.php
Line: 230
Function: require_once