How to validate captcha field code? - php

Question

I am trying to validate a captcha code field so if the code they enter is correct it will take them to a thank you page with the download link, but if the security code they entered is incorrect then they will see a sorry message and to return back to previous page.
The issue I am facing is when I enter the captcha into this field and click submit the data is always no.
My form is a as follows:
<form action="" name="downloadform" id="downloadform" class="downloadform" method="post">
<div class="field">
<input name="name" type="text" id="name" class="input name" placeholder="Name..." />
</div>
<div class="field">
<input name="company" type="text" id="company" class="input company" placeholder="Company..." />
</div>
<div class="field">
<input name="tel" type="text" id="tel" class="input tel" placeholder="Telephone..." />
</div>
<div class="field">
<input name="email" type="text" id="email" class="input email" placeholder="Email Address..." />
</div>
<div class="field">
<img src="/CaptchaSecurityImages.php" alt="Captcha" class="captcha" />
<input type="text" name="sec_code" id="sec_code" class="input sec_code" placeholder="Please enter the characters above" />
</div>
<div class="field">
<div class="medium secondary btn"><input type="submit" name="Submit2" value="Send Request" class="btn" id="downloadbtn" /></div>
<input type="hidden" name="product" id="product" class="product" value="<?php echo $page[3]; ?>" />
</div>
</form>
My ajax form file looks like this:
$(function() {
filter = /^([a-zA-Z0-9_\.\-])+\#(([a-zA-Z0-9\-])+\.)+([a-zA-Z0-9]{2,4})+$/;
$("#downloadbtn").click(function() {
var name = $("#name").val();
var company = $("#company").val();
var tel = $("#tel").val();
var email = $("#email").val();
var product = $("#product").val();
var sec_code = $("#sec_code").val();
if (name == "") {
$("#name").focus();
$("#name").val("");
$("#name").css({background:"#b72a18", color:"#fff"});
return false;
}
if (company == "") {
$("#company ").focus();
$("#company ").val("");
$("#company ").css({background:"#b72a18", color:"#fff"});
return false;
}
if (tel == "") {
$("#tel").focus();
$("#tel").val("");
$("#tel").css({background:"#b72a18", color:"#fff"});
return false;
}
if (!filter.test(email)) {
$("#email").focus();
$("#email").val("");
$("#email").css({background:"#b72a18", color:"#fff"});
return false;
}
if (product == "") {
$("#product").focus();
$("#product").val("");
$("#product").css({background:"#b72a18", color:"#fff"});
return false;
}
if (sec_code == "") {
$("#sec_code").focus();
$("#sec_code").val("");
$("#sec_code").css({background:"#b72a18", color:"#fff"});
return false;
}
$('.downloadform').html('<center><img src="/images/ajax-loader.gif" style="padding:20px;"></center>');
var dataString = '&name=' + name + '&tel=' + tel + '&company=' + company + '&email=' + email + '&product=' + product + '&sec_code=' + sec_code + '&type=download';
//alert (dataString);return false;
$.ajax({
type: "POST",
url: "/process_download.php",
data: dataString,
datatype: 'json',
success: function(data) {
$('.downloadform').html('<center><img src="/images/ajax-loader.gif" style="padding:20px;"></center>')
.hide()
.fadeIn(1500, function() {});
setTimeout(function ()
{
$(window.location).attr('href', '/process.php?download=' + data.product + '&sec_code=' + data.sec_code);
}, 2000);
}
});
return false;
});
});
Then I have my process download file:
<?php
session_start();
header("Content-type: application/json");
ob_start();
include('inc/connection.php');
$product = $_POST['product'];
$sec_code = $_SESSION['security_code'] == $_POST['sec_code'] ? 'yes' : 'no';
ob_end_clean();
$data = array('product'=>$product,'sec_code'=>$sec_code);
print json_encode($data);
die();
?>
Then the final process:
<?php
session_start();
include('inc/connection.php');
$sec_code = $_GET['sec_code'];
$proddownlink = $_GET['download'];
$proddownl = str_replace("_", " ", $_GET['download']);
$proddownl = ucwords($proddownl);
if ($sec_code == 'no') {
$message = '<p>Security code is wrong. Please click here to return back.</p>';
} else {
$message = '<p>Thank you for downloading ' . $proddownl . ' Data Sheet.</p>
<p>Please click here to download ' . $proddownl . ' PDF.</p>';
include_once('inc/connection.php');
include_once('inc/class.phpmailer.php');
$name = $_POST['name'];
$company = $_POST['company'];
$tel = $_POST['tel'];
$email = $_POST['email'];
$product = $_POST['product'];
$sec_code = $_POST['sec_code'];
$type = $_POST['type'];
$bodytext = "<ul>
<li><strong>Name:</strong> $name</li>
<li><strong>Company:</strong> $company</li>
<li><strong>Telephone Number:</strong> $tel</li>
<li><strong>Email Address:</strong> $email</li>
<li><strong>Area of Interest:</strong> $product</li>
</ul>";
$subject = "New Enquiry";
$query = "insert into user_email set name = '$name', email = '$email', tel = '$tel', type = '$type', message = '$bodytext'";
$result = $conn->query($query);
if(!$result) die($conn->error);
$mail = new PHPMailer(); // defaults to using php "mail()"
$body = $bodytext;
$mail->From = "sales#fidelitysystems.co.uk";
$mail->FromName = $name;
$mail->Subject = $subject;
$mail->AltBody = "To view the message, please use an HTML compatible email viewer!";
$mail->MsgHTML($body);
#$mail->AddAddress("sales#fidelitysystems.co.uk");
$mail->AddAddress("craig#arrivaldesign.co.uk");
$mail->IsSMTP();
$mail->SMTPAuth = "true";
$mail->Username = "postmaster#arrivalbusiness.co.uk";
$mail->Password = "edward";
$mail->Host = "mail.arrivalbusiness.co.uk";
$mail->Port = 587;
if(!$mail->Send()) {
echo "Mailer Error: " . $mail->ErrorInfo;
}
}
?>