index.php

<?php include 'header.php'; ?>
	<div class="container">
		  <div class="row">
		     <div class="col-md-6 offset-md-3 mt-4 shadow">
			      <form method="POST" class="bg-white p-5" action="form.php">
              <h2>PROVE! YOU ARE NOT A ROBOT!!</h2><hr>
              <strong class="alert alert-danger text-muted pt-2">
                Type the text in the image to prove
                you are not a robot
              </strong>
              <img style="display: block; margin: 10%;" src="captcha.php" alt="image verification" />
              <input type="text" id="captchha" name="captcha" size="20" maxlength="6" class="form-control m-1">
              <input type="submit" value="Submit" class="btn btn-success col-12 m-1">
                <?php
                /*if captcha code is posted*/
                if(isset($_POST["captcha"]))					
                  if($_SESSION["captcha"]==strtolower($_POST["captcha"])):/*CAPTCHA is valid. You can process the form now.*/?>
                  <p class="text-success"> CAPTCHA is valid. You can process the form now.</p>
                <?php else: /*Invalid CAPTCHA*/ ?>
                  <p class="text-danger">Invalid <strong>CAPTCHA.</strong> Pls Try again!</p>
                <?php endif; ?>
                <div>
                  Can't read the image? Click
                  <a style="text-decoration: none" href='<?= $_SERVER['PHP_SELF']; ?>'>
                    <i class="fa fa-sync"></i>
                  </a>
                  to refresh!
		            </div>
		        </form>
		     </div>
	    </div>
	</div>
<?php include 'footer.php'; ?>