A PHP Error was encountered

Severity: Notice

Message: Undefined index: HTTP_ACCEPT_LANGUAGE

Filename: models/Lang_model.php

Line Number: 54

Backtrace:

File: /var/www/vhosts/khtessence.com.tw/httpdocs/application/models/Lang_model.php
Line: 54
Function: _error_handler

File: /var/www/vhosts/khtessence.com.tw/httpdocs/application/models/Lang_model.php
Line: 31
Function: accept_language

File: /var/www/vhosts/khtessence.com.tw/httpdocs/application/models/Cart_model.php
Line: 13
Function: get_lang

File: /var/www/vhosts/khtessence.com.tw/httpdocs/application/controllers/Home.php
Line: 10
Function: model

File: /var/www/vhosts/khtessence.com.tw/httpdocs/index.php
Line: 315
Function: require_once