Google reCaptcha v2


<!-- 
Step 1:
https://www.google.com/recaptcha/admin/create
-->

<!-- Step 2: This file -->
<html>
  <head>
    <title>Google reCaptcha v2 Demo</title>
    <script src='https://www.google.com/recaptcha/api.js'></script>
  </head>
  <body>
    <h1>Google reCAPTHA Demo</h1>
    <form id="comment_form" action="form-post.php" method="post">
      ...
      <div class="g-recaptcha" data-sitekey="SITE_KEY"></div>
      <input type="submit" name="submit" value="Submit"><br><br>
    </form>
  </body>
</html>

<!-- Step 3: form-post.php -->
<?php

    // $response=file_get_contents("https://www.google.com/recaptcha/api/siteverify?secret=SECRET_KEY&response=".$captcha."&remoteip=".$_SERVER&#91;'REMOTE_ADDR'&#93;);
    // if($response.success==true)            
    // {
    //   echo '<h2>Thanks for posting comment.</h2>';
    // }

    if(isset($_POST['g-recaptcha-response'])){
      $captcha = $_POST['g-recaptcha-response'];
    }

    if(!$captcha){
      echo '<h2>Please check the captcha.</h2>';
      exit;
    }
    else {
      echo '<h2>Thanks for posting.</h2>';
    }

?>