pake captcha

<?php
//controller
function regis()
{
        $this->load->model('usermodel');
        $d['captcha']=$this->usermodel->captcha();
        $this->load->view('basic_view',$d);

}
//MODELnya
class usermodel extends CI_Model
{
/*
sebelumnya.. pastikan kamu udah punya folder tmp!!
silakan ganti pake nama lain..
Membuat Captcha
1. Captcha
2. request id dan input ke database
3. hapus captcha yg lama
*/
    function captcha()
    {
        $this->load->helper('captcha');
        $vals = array(
        'img_path'   => 'tmp/',
        'img_url'    => '/jasakeren/tmp/'
        );
/*
Sebelum lanjut.. pastikan kamu udah setting segala yg berhubungan ama
captcha dahulu..
*/
        $cap = create_captcha($vals);
        $cap['id']=$this->captcha_id($cap);
        $this->hapus_captcha(); //optional bisa di ignore..
        return $cap;

    }

    function captcha_id($a)
    {

/*
    Kamu bisa simpan di session tetapi tidak menutup kemungkinan
diletakkan di table..
CREATE TABLE  `work_jk`.`my_captcha` (
`c_id` INT NOT NULL autoincrement,
`c_word` VARCHAR( 20 ) NOT NULL ,
`c_time` TIMESTAMP NOT NULL DEFAULT CURRENT_TIMESTAMP ,
PRIMARY KEY (  `c_id` )
) ENGINE = MYISAM
Array ( [word] => bBLbQNiC [time] => 1333946701.87);
krn saya dah terlanjur pake table.. coba pake dulu aja
*/

        $data=array(
        'c_word'=>$a['word'],
        'c_time'=>$a['time']
        );
/* bukan c_date */
        $this->db->insert('my_captcha', $data);

        return $this->db->insert_id();

    }

    /*
    Hapus yang tidak terpakai
    */
    function hapus_captcha()
    {
        $now=date("Y-m-d H:i:s", mktime()-7200);
        $q=$this->db->query("select * from my_captcha where c_time<'$now'");
        foreach ($q->result_array() as $row)
        {
            $sql="delete from my_captcha where c_id=".$row['c_id'];
            $q2=$this->db->query($sql);
            unlink("tmp/".$row['c_date'].".jpg")?$r=1:die('tidak ada yg dihapus');
        }

    }
}
?>
//=========VIEWnya
<? print_r ($captcha); ?>