A PHP Error was encountered

Severity: Notice

Message: Undefined index: series_slug

Filename: helpers/required_helper.php

Line Number: 216

Backtrace:

File: /home/freetuts/public_html/sources/helpers/required_helper.php
Line: 216
Function: _error_handler

File: /home/freetuts/public_html/site/controllers/tut/Homework.php
Line: 44
Function: link_tut_series

File: /home/freetuts/public_html/sources/index.php
Line: 297
Function: require_once

File: /home/freetuts/public_html/index.php
Line: 23
Function: require_once