Adding a captcha to a basic form

[wright67uk]

I have a basic question for anyone that can help me.

Ive added a captcha input field to the form below, as Im having problems with spam appearing on my testimonial page.

 

1) How can I prevent the form from being sent if the wrong or no answer is in the form field.

2) How can i have a message appear saying "Sorry wrong answer" if the from isnt sent for the above reason?

 

add.php

<form method="post" action="process2.php" >
<textarea rows="25" cols="100" wrap="physical" name="data">
</textarea>
<input type="hidden" name="area" value="testimonial"/> 
What is 5+5?
<input type="text" name="captcha"/>
<input type="submit" value="Add ">
</form>

 

process2.php

<p class="add">Thankyou for submitting your testimonial;</br>
<?php $data="<br><br>" . $_POST["data"]; ?><br />
<?php $area=$_POST["area"]; ?>
<?php echo $data; ?></p>

<?php mysql_query("UPDATE wheelchairwizard SET data = CONCAT(data, '$data') WHERE area = '$area'"); ?>

</br>
Return to the testimonial page - <a href="http://www.wheelchairwizard.co.uk/testimonials.php">click here</a>

[smerny]

if($_POST['captcha'] == 10){
  //output like you have now
}
else
{
  //telll them they entered the wrong thing
}

 

thats not a very secure captcha though, if you want something more secure, google "php captcha tutorial" or something

[BigTime]

following up on smearny... Google around for math captcha and you will find a full code that randomizes that process into numbers and text.

 

I haven't gotten a single piece of spam on a form I implemented with that in 3 years.

 

Theres also a nifty picture puzzle captcha that works quite well also and is probably easier to implement called key captcha .

[Zane]

I'm not going to tell you to give up on making your CAPTCHA system, but I will suggest that you make use of a system that's already stable... and FREE

http://www.google.com/recaptcha

 

If you're looking for a not-so-difficult version, then check these out

http://woork.blogspot.com/2009/02/10-free-captcha-scripts-and-services.html

 

 

To put it short, there's no point re-inventing the wheel unless that wheel is revolutionary.