Recaptcha Bug Loop

Question

我开始研究recaptcha文件，但这个文件不断循环（不知道为什么）。

    <?php

    if (!defined('QA_VERSION')) { // don't allow this page to be requested directly from browser
        header('Location: ../');
        exit;
    }


    class qa_recaptcha_captcha {

        var $directory;

        function load_module($directory, $urltoroot)
        {
            $this->directory=$directory;
        }


        function admin_form()
        {
            $saved=false;

            if (qa_clicked('recaptcha_save_button')) {
                qa_opt('recaptcha_public_key', qa_post_text('recaptcha_public_key_field'));
                qa_opt('recaptcha_private_key', qa_post_text('recaptcha_private_key_field'));

                $saved=true;
            }

            $form=array(
                'ok' => $saved ? 'reCAPTCHA settings saved' : null,

                'fields' => array(
                    'public' => array(
                        'label' => 'reCAPTCHA public key:',
                        'value' => qa_opt('recaptcha_public_key'),
                        'tags' => 'name="recaptcha_public_key_field"',
                    ),

                    'private' => array(
                        'label' => 'reCAPTCHA private key:',
                        'value' => qa_opt('recaptcha_private_key'),
                        'tags' => 'name="recaptcha_private_key_field"',
                        'error' => $this->recaptcha_error_html(),
                    ),
                ),

                'buttons' => array(
                    array(
                        'label' => 'Save Changes',
                        'tags' => 'name="recaptcha_save_button"',
                    ),
                ),
            );

            return $form;
        }


        function recaptcha_error_html()
        {
            if (!function_exists('fsockopen'))
                return 'To use reCAPTCHA, the fsockopen() PHP function must be enabled on your server. Please check with your system administrator.';

            elseif ( (!strlen(trim(qa_opt('recaptcha_public_key')))) || (!strlen(trim(qa_opt('recaptcha_private_key')))) ) {
                require_once $this->directory.'recaptchalib.php';

                $url=recaptcha_get_signup_url(@$_SERVER['HTTP_HOST'], qa_opt('site_title'));

                return 'To use reCAPTCHA, you must <a href="'.qa_html($url).'">sign up</a> to get these keys.';
            }

            return null;                
        }


        function allow_captcha()
        {
            return function_exists('fsockopen') && strlen(trim(qa_opt('recaptcha_public_key'))) && strlen(trim(qa_opt('recaptcha_private_key')));
        }


        function form_html(&$qa_content, $error)
        {
            require_once $this->directory.'recaptchalib.php';

            $language=qa_opt('site_language');
            if (strpos('|en|nl|fr|de|pt|ru|es|tr|', '|'.$language.'|')===false) // supported as of 3/2010
                $language='en';

            $qa_content['script_lines'][]=array(
                "var RecaptchaOptions={",
                "\ttheme:'white',",
                "\tlang:".qa_js($language),
                "};",
            );

            return recaptcha_get_html(qa_opt('recaptcha_public_key'), $error, qa_is_https_probably());
        }


        function validate_post(&$error)
        {
            if ( (!empty($_POST['recaptcha_challenge_field'])) && (!empty($_POST['recaptcha_response_field'])) ) {
                require_once $this->directory.'recaptchalib.php';

                $answer=recaptcha_check_answer(
                    qa_opt('recaptcha_private_key'),
                    qa_remote_ip_address(),
                    $_POST['recaptcha_challenge_field'],
                    $_POST['recaptcha_response_field']
                );

                if ($answer->is_valid)
                    return true;

                $error=@$answer->error;
            }

            return false;
        }

    }

因此我收到内部服务器错误。可能是什么问题？请帮我。我坐在这第三天，我想也许我错过了一些明显的东西。