A PHP Error was encountered

Severity: Notice

Message: Undefined index: HTTP_REFERER

Filename: controllers/Wechat_api.php

Line Number: 19

Backtrace:

File: D:\WEB_51TTYY\Mobile\mobile\controllers\Wechat_api.php
Line: 19
Function: _error_handler

File: D:\WEB_51TTYY\Mobile\mobile.php
Line: 292
Function: require_once

/*wrong visit*/