adding a captcha to guestbook submission form - php

Question

I am trying to add a captcha to my guestbook submission form but cannot get the if(($_POST['code']) == ($_SESSION['code'])) statement to work. Please see code below. Any help would be greatly appreciated.
if ($_POST['postbtn']){
$name = strip_tags($_POST['name']);
$email = strip_tags($_POST['email']);
$comment = strip_tags($_POST['comment']);
if(($_POST['code']) == ($_SESSION['code'])) {
$code = strip_tags($_POST['code']);
}
if($name && $email && $comment && $code){
$time = date("h:i A");
$date = date("F d, Y");
$ip = $_SERVER['REMOTE_ADDR'];
// add to the database
mysqli_query($con,"INSERT INTO guestbook VALUES (
'', '$name', '$email', '$comment', '$time', '$date', '$ip'
)");
echo "Your post has been added.";
}
else
echo"You did not enter in all the required info.";
}
echo "<form action='./index.php' method='post'>
<table>
<tr>
<td>Name:</td>
<td><input type='text' name='name' style='width: 200px;' /></td>
</tr>
<tr>
<td>Email:</td>
<td><input type='text' name='email' style='width: 200px;' /></td>
</tr>
<tr>
<td>Comment:</td>
<td><textarea name='comment' style='width: 197.5px; height: 50px;'>
</textarea></td>
</tr>
<tr>
<td><img src='captcha.php?'/></td>
<td><input type='text' name='code' style='width: 200px;' /></td>
</tr>
<tr>
<td></td>
<td><input type='submit' name='postbtn' value='Post' /></td>
</tr>
</table>
</form>";

Answer 1

Can you try echo on both $_POST['code'] and $_SESSION['code'] so that you can debug it and see if you are getting the values correctly? I don't think you are getting them right. if not just add up a complete scenario here with proper field names and values.