CodeIgniter unos podataka i njihova obrada

Gde je greska:

www.sabiranje.php u delu controllers je:

<?php
class Sabiranje extends CI_Controller {

function index()
{
echo "Sabiranje 2 broja "."</br>"."</br>";
$this->load->view('sabiranje_view');
}
}
?>



www.sabiranje_view.php u delu views je:



<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<title>Sabiranje 2 broja</title>
<style type="text/css">
<!--
body,td,th {
font-family: Arial, Helvetica, sans-serif;
}
-->
</style></head>

<body>
<form id="form1" name="form1" method="post" target="_self" action="http://localhost/CodeIgniter/index.php/sabiranje"/>
<label>Broj 1:
<input type="text" name="br1" value="<?php echo $_POST["br1"] ?>" />
</label>
<p>
<label>Broj 2:
<input type="text" name="br2" value="<?php echo $_POST["br2"] ?>" />
</label>
</p>

<p>
<label>Rezultat :
<input type="text" name="rez" value="<?php $rez=$br1+$br2; echo $rez; ?>" />
</label>
</p>

<label>
<input type="submit" name="Šalji !" value="Submit" />
</label>
</form>
</body>
</html>


Kako da pravilno unesem podatke i da ih obradim

Nisam koristio Codeigniter pa mozda gresim. Ali zasto "stampas" nesto u kontroleru pa load-ujes view?
I koliko vidim nigde nisi dodelila vrednost promenljivima $br1 i $br2.