A PHP Error was encountered

Severity: Notice

Message: Undefined offset: -1

Filename: frontend/C_f_frontend.php

Line Number: 11

Backtrace:

File: /home/tkwebctho/domains/thietkewebcantho.com/public_html/xongtamdaodo/application/controllers/frontend/C_f_frontend.php
Line: 11
Function: _error_handler

File: /home/tkwebctho/domains/thietkewebcantho.com/public_html/xongtamdaodo/index.php
Line: 315
Function: require_once