if ( isset( $_POST[ 'login' ] ) )
{

$kullanici_adi = $_POST['kullanici'];
$kullanici_pass = $_POST['sifre'];

    if ( $kullanici_adi && $kullanici_pass )
    {


        $kullanicisor = $db->prepare( "SELECT *,ayar.$admin[1] as kullanici,ayar.$admin[2] as sifre FROM ticaret where id=2");

        $yonet=$kullanicisor['ayar'];
        $admin= explode('^',$yonet);

        $kullanicisor->execute(
            array(
                $admin[1] => $kullanici_adi,
                $admin[2] => $kullanici_pass
            )
        );

        $say = $kullanicisor->rowCount();

        if ( $say > 0 )
        {

            $_SESSION[$admin[1]] = $kullanici_adi;

            header( 'Location:./anasayfa.php' );
        }
        else {header( 'Location:./index.php?status=no' );}
    }
}

<form class="form-horizontal form-material" id="loginform" action="fonksiyonlar.php" method="POST">


<h3 class="box-title m-b-20" style="color:white;">Yetkili Girişi</h3>
<div class="form-group ">
<div class="col-xs-12">
<input class="form-control" name="kullanici" type="text" required="" placeholder="Kullanıcı Adı"> </div>
</div>
<div class="form-group">
<div class="col-xs-12">
<input class="form-control" name="sifre" type="password" required="" placeholder="Şifre"> </div>
</div>

<div class="form-group text-center m-t-20">
<div class="col-xs-12">
<button name="login" class="btn btn-info btn-lg btn-block text-uppercase waves-effect waves-light" type="submit">Giriş yap</button>
</div>
</div>

                </form>