extending controllers

[eluser]Dimitrio[/eluser]

if ($this->data->user === FALSE) {
header('Location: '.$this->config->item('base_url').'login');

I am very new to CI, can someone please explain to me what the "$this->data->user" is, and where CI gets it from,

as well as the "header".

I am trying to use erkana auth to only show a menu in my Header_view if the person is logged in, but I keep on getting errors, I think I might be able to solve it once I understand these two concepts.

Thnx