Why my session is not working with error message-Cannot modify header information

[eluser]Dam1an[/eluser]
If you use CI sessions, it will return false if you try to get something which hasn't been set, so you can do something like

Code:

if($this->session->userdata('logged_in')) {
  echo 'Welcome ', $this->session->userdata('user_name');
} else {
  echo 'Welcome guest';
}

(You could also rewrite this using a ternary operator if you prefer)