reCaptcha没有正确输入

Question

我想为我的联系表单添加reCaptcha，但它不起作用。我总是得到reCaptcha没有正确输入！

这是我的网站：http://ramzi-bk.net84.net/

在cantact.php中

<form action="">
...
<div class="box-wrapper" id="recaptcha_div"></div>
<input value="Envoyer" class="submit btn-form" id="submit" type="submit"/>
</form>

在external.js

中

var options = {
            type: "POST",
            url:            'service/sendMail.php',             // override for form's 'action' attribute 
            error:          mailError,
            success:        mailResponse,               // post-submit callback 
            beforeSubmit:   validate, 
            clearForm: false,                               // clear all form fields after successful submit 
            resetForm: false,                               // reset the form after successful submit 
        };
        $('#contactForm').ajaxForm(options);

function mailResponse(data,textStatus,xhr,jqXHR){
    showMsg(data);
}
function mailError(jqXHR,textStatus,errorThrown){
    showMsg(errorThrown);
}

function showRecaptcha(element) {
           Recaptcha.create("**********************", element, {
             theme: "white",
             callback: Recaptcha.focus_response_field});
    }

showRecaptcha("recaptcha_div");

在sendMail.php中

<?php
require_once('../lib/recaptchalib.php');
$privatekey="***********************";
$resp=recaptcha_check_answer($privatekey,
                             $_SERVER["REMOTE_ADDR"],
                             $_POST["recaptcha_challenge_field"],
                             $_POST["recaptcha_response_field"]);
if(!$resp->is_valide){
    echo "The reCAPTCHA wasn't entered correctly: ".$resp->error;
}else{
   /* Envoi de l'e-mail */
    if(mail($to, $subject, $msg, $headers)==true){
        echo "Votre message a été envoyé.";
    }else{
        echo "Une erreur s'est produite lors de l'envoi de votre message.";
    }
    /* clear form variables*/
    unset($_POST);
}

请帮忙。