php codeigniter framework kullanıyorum. admin panele giriş yaparken kullanıcı adı ve şifreyi doğru veya yanlış yazmama rağmen sürekli kullanıcı adı veya şifre hatalı olarak tanımladığım hata mesajını alıyorum bir türlü çözemedim acil yardım lütfen. kodları aşağıya bırakıyorum.

controller/admin/login.php kodlarım;

<?php
defined('BASEPATH') OR exit('No direct script access allowed');


class Login extends CI_Controller {

public function __construct()
{
parent::__construct();
$this->load->helper('url');
$this->load->database();

}



public function index()
{
$this->load->view('admin\login_form');





}
public function login_ol()
{
$kullanici= $this->input->post("kullanici");
$sifre= $this->input->post("sifre");


$kullanici = $this->security->xss_clean($kullanici);
$sifre = $this->security->xss_clean($sifre);
$this->load->model('Database_Model');





$result= $this->Database_Model->login("admin",$kullanici,$sifre);

if($result){
echo "Şifre Doğru";


}
else
{
$this->session->set_flashdata("mesaj","Hatalı kullanıcı adı yada şifre!!");
redirect(base_url().'admin/login');
}


}


}


views/admin/login_form.php kodlarım;

<!DOCTYPE html>
<!--[if IE 8]> <html lang="en" class="ie8"> <![endif]-->
<!--[if IE 9]> <html lang="en" class="ie9"> <![endif]-->
<!--[if !IE]><!--> <html lang="en"> <!--<![endif]-->
<!-- BEGIN HEAD -->
<head>
<meta charset="utf-8" />
<title>Login</title>
<meta content="width=device-width, initial-scale=1.0" name="viewport" />
<meta content="" name="description" />
<meta content="" name="author" />
<link href="<?=base_url()?>assets/admin/bootstrap/css/bootstrap.min.css" rel="stylesheet" />
<link href="<?=base_url()?>assets/admin/bootstrap/css/bootstrap-responsive.min.css" rel="stylesheet" />
<link href="<?=base_url()?>assets/admin/font-awesome/css/font-awesome.css" rel="stylesheet" />
<link href="<?=base_url()?>assets/admin/css/style.css" rel="stylesheet" />
<link href="<?=base_url()?>assets/admin/css/style-responsive.css" rel="stylesheet" />
<link href="<?=base_url()?>assets/admin/css/style-default.css" rel="stylesheet" id="style_color" />
</head>
<!-- END HEAD -->
<!-- BEGIN BODY -->
<body class="lock">
<div class="lock-header">
<!-- BEGIN LOGO -->
<a class="center" id="logo" href="index.html">
<img class="center" alt="logo" src="<?=base_url()?>/img/logo.png">

<?php if ($this->session->flashdata("mesaj"))
{?>

<div class="alert alert-block alert-error fade in">
<button data-dismiss="alert" class="close" type="button">×</button>
<h4 class="alert-heading">HATA!</h4>
<p>
<?=$this->session->flashdata("mesaj")?>
</p>
</div>
<?php } ?>
</a>
<!-- END LOGO -->
</div>
<div class="login-wrap">
<div class="metro single-size red">
<div class="locked">
<i class="icon-lock"></i>
<span>Login</span>
</div>
</div>
<div class="metro double-size green">
<form action="index.html">
<div class="input-append lock-input">

<input type="text" name="kullanici" required class="" placeholder="Kullanıcı Adı">
</div>
</form>
</div>
<div class="metro double-size yellow">
<form action="index.html">
<div class="input-append lock-input">
<input type="password" name="sifre" required class="" placeholder="Şifre">
</div>
</form>
</div>
<div class="metro single-size terques login">


<form action="<?=base_url()?>admin/login/login_ol">
<button type="submit" class="btn login-btn">
Login
<i class=" icon-long-arrow-right"></i>
</button>
</form>
</div>
<div class="login-footer">
<div class="remember-hint pull-left">
<input type="checkbox" id=""> Remember Me
</div>
<div class="forgot-hint pull-right">
<a id="forget-password" class="" href="javascript:;">Forgot Password?</a>
</div>
</div>
</div>
</body>
<!-- END BODY -->
</html>