A PHP Error was encountered

Severity: Notice

Message: Undefined index: HTTP_REFERER

Filename: controllers/User.php

Line Number: 160

Backtrace:

File: /var/www/vhosts/chamt.com.tw/httpdocs/application/controllers/User.php
Line: 160
Function: _error_handler

File: /var/www/vhosts/chamt.com.tw/httpdocs/index.php
Line: 321
Function: require_once