Math captcha image form validation. All the captcha script resides in index.php. To implement this, all you need to do is add the captcha image to your forms ( <img src="math_captcha_path/image.php" /> ) and do the form validation.
Captha result is stored in session, so remember to start your session with the same name, if any used.
For this to work, you need PHP installed with GD support and ttftext. Remember to add the font used in your captcha.