controller

public function developer(){
            $this->form_validation->set_error_delimiters('<div class="error">', '</div>');
            $this->form_validation->set_rules('full_name', 'Full Name', 'trim|required|xss_clean');
            $this->form_validation->set_rules('lahir', 'Birthday', 'trim|required|xss_clean');
            $this->form_validation->set_rules('hp', 'Hadphone', 'trim|required|xss_clean');
            $this->form_validation->set_rules('alamat', 'Alamat', 'trim|required|xss_clean');
            $this->form_validation->set_rules('email', 'Email', 'trim|required|xss_clean');
            $this->form_validation->set_rules('secutity_code', 'Captcha', 'callback_validate_captcha');

            if($this->form_validation->run() == FALSE) {

                $original_string = array_merge(range(0,9), range('a','z'), range('A', 'Z'));
                $original_string = implode("", $original_string);
                $captcha = substr(str_shuffle($original_string), 0, 6);

                $vals = array(
                    'word' => $captcha,
                    'img_path'   => './captcha/',
                    'img_url'    => base_url().'captcha/',
                    'img_width'  => '245',
                    'img_height' => 30,
                    'border' => 0,
                    'expiration' => 7200
                );

                // create captcha image
                $cap = create_captcha($vals);

                // store image html code in a variable
                $data['image'] = $cap['image'];

                // store the captcha word in a session
                $this->session->set_userdata('mycaptcha', $cap['word']);

                $this->load->view('signup_developer', $data);
            } else {
                if(file_exists(BASEPATH."../captcha/".$this->session->userdata['image']))
                    unlink(BASEPATH."../captcha/".$this->session->userdata['image']);

                $this->session->unset_userdata('mycaptcha');
                $this->session->unset_userdata('image');
                redirect('developer', 'refresh');
            }
        }
        public function developer_() {
            if ($this->input->post() && ($this->input->post('secutity_code') == $this->session->userdata('mycaptcha'))) {
                $full_name = $this->input->post('full_name');
                $lahir = $this->input->post('lahir');
                $hp = $this->input->post('hp');
                $alamat = $this->input->post('alamat');
                $email = $this->input->post('email');
                $pass = $this->input->post('pass');

                $cekdataagen = $this->db->query("SELECT * FROM user where nama='".$full_name."' AND email='".$email."'");
                $count = $cekdataagen->num_rows;

                if($count == 1){
                    $this->session->set_flashdata('checking_data', 'Warning : Already Account.');
                    redirect('signup/developer');
                } else {
                    $insert = $this->db->insert('user',array(
                        'level' => 'DEVELOPER',
                        'nama' => $full_name,
                        'tgl_lahir' => $lahir,
                        'nohp' => $hp,
                        'alamat' => $alamat,
                        'email' => $email,
                        'pass' => md5($pass),
                        'pass_' => $pass,
                        'date_reg' => date('Y-m-d H:i:s'),
                        'status' => 0
                    ));
                    $this->session->set_flashdata('sukses_register', '<b>Thank You</b><br> Admin Akan Menghubungi Anda Dalam Jangka Waktu (2x24) Untuk Verifikasi Data.');
                    redirect('signup/developer');
                }
            } else {
                $vals = array(
                    'img_path'   => './captcha/',
                    'img_url'    => base_url().'captcha/',
                    'img_width'  => '245',
                    'img_height' => 30,
                    'border' => 0,
                    'expiration' => 7200
                );

                // create captcha image
                $cap = create_captcha($vals);

                // store image html code in a variable
                $data['image'] = $cap['image'];

                // store the captcha word in a session
                $this->session->set_userdata('mycaptcha', $cap['word']);

                $this->session->set_flashdata('invalid_captcha', 'Captcha Code Invalid');
                redirect('signup/developer');
            }
        }