This is really weird. Whenever I call something like if(empty($this->input->post("foo")){//blabla} The whole PHP is "down" and I get a blank page from the website (even when I don't pass through this empty(input) line). I know this is not the right method and it is stupid, I change the code to if(!$this->input->post("foo")){//blabla} Better I guess ? Seriously, how come the empty(input) breaks down the entire PHP page ? (I can't get any echo "something").