A PHP Error was encountered

Severity: Notice

Message: Undefined index:

Filename: controllers/Xx.php

Line Number: 99

Backtrace:

File: /var/www/hunchun123/application321/controllers/Xx.php
Line: 99
Function: _error_handler

File: /var/www/hunchun123/index.php
Line: 292
Function: require_once