Code Captcha No

1.class-captcha.php

<?php
session_start();

class mathcaptcha
{
private $bil1;
private $bil2;
private $operator;

function initial(){
        $listoperator = array('+', '-', 'x');
        $this->bil1 = rand(0, 99);
        $this->bil2 = rand(0, 99);
        $this->operator = $listoperator[rand(0, 2)];
}

function generatekode(){
        $this->initial();

        if ($this->operator == '+') $hasil = $this->bil1 + $this->bil2;
        else if ($this->operator == '-') $hasil = $this->bil1 - $this->bil2;
        else if ($this->operator == 'x') $hasil = $this->bil1 * $this->bil2;
        $_SESSION['kode'] = $hasil;
    }

function showcaptcha(){
        echo "Hasil dari &nbsp;<big><b style=color:#0ec4f7;>".$this->bil1." ".$this->operator." ".$this->bil2."</b></big>&nbsp;&nbsp;? ";
    }   

function resultcaptcha(){
        return $_SESSION['kode'];
    }

}
?>

2.index.php

<?php
    include 'class-captcha.php';
    $captcha1 = new mathcaptcha();
    $captcha1->generatekode();
    $captcha1->showcaptcha();


 source untuk validasi........


include 'class-captcha.php';
$captcha1 = new mathcaptcha();
$kode     = $_POST['kode'];

else
if ($captcha1 -> resultcaptcha() == $kode){
//-----------pesan ok
}else {
//------------pesan error
}
?>

Hanyep............................................................!!!