How to exit() ?

[eluser]danmontgomery[/eluser]
*cough*

Code:

function index(){
  if(UNDER_MAINTENANCE) {
    $this->_maintenance();
  else
    $this->_normal();
  }
}

function _maintenance(){
  $this->load->view('under_maintenance');
}

function _normal(){
  $this->load->view('index');  
}