A PHP Error was encountered

Severity: Notice

Message: Undefined index: HTTP_USER_AGENT

Filename: libraries/Mylibrary.php

Line Number: 147

Backtrace:

File: E:\server.tiga\application\libraries\Mylibrary.php
Line: 147
Function: _error_handler

File: E:\server.tiga\application\controllers\News.php
Line: 18
Function: __construct

File: E:\server.tiga\index.php
Line: 294
Function: require_once