A PHP Error was encountered

Severity: Notice

Message: Undefined variable: user_id

Filename: frontend/header.php

Line Number: 255

Backtrace:

File: /home/qoloni21/public_html/application/views/frontend/header.php
Line: 255
Function: _error_handler

File: /home/qoloni21/public_html/application/views/frontend/main.php
Line: 221
Function: view

File: /home/qoloni21/public_html/application/controllers/Profile.php
Line: 170
Function: view

File: /home/qoloni21/public_html/index.php
Line: 297
Function: require_once