A PHP Error was encountered

Severity: Notice

Message: Undefined index: HTTP_USER_AGENT

Filename: libraries/Mylibrary.php

Line Number: 157

Backtrace:

File: /home/u7195769/public_html/application/libraries/Mylibrary.php
Line: 157
Function: _error_handler

File: /home/u7195769/public_html/application/controllers/News.php
Line: 9
Function: __construct

File: /home/u7195769/public_html/index.php
Line: 315
Function: require_once