[========================< Image Validator 1.0 >=============================]
[                                                                            ]
[                     Copyright 2007 Image Validator                         ]
[                  Pavel Tzonkov <pavelc@users.sf.net>                       ]
[                      Hosted at http://gscripts.net                         ]
[============================================================================]

I. DESCRIPTION

    Image Validator is a GPL CAPTCHA php script to stop spam on  any form: comment areas,
    signups, shopping carts - any area of your website where you fear the evil spammers may target.


II. REQUIREMENTS

    1. Apache 1 or 2
    2. PHP 4 or 5
    3. GD 2 with truetype support


III. INSTALLATION

    0. Unpack this package.
    1. You may edit _config.php file located in imgval directory.
    2. You may copy some TrueType fonts in imgval/fonts directory.
    2. Upload or copy imgval directory to browsable directory.
    3. Open imgval/index.php in your browser for testing.


IV. INTEGRATION NOTES

    In <img> tag, 'src' parametter should be linked with imgval/code.php.

    Example: <img src="imgval/code.php" />.

    To prevent cache images you may add some unique parametter.

    Example: <img src="imgval/code.php?id=<?= time() ?>" />

    Your should start a session in the response PHP file. In the valid action
    PHP source code you should verify MD5 sum of the input-code-field-value
    with session variable named __img_code__

    Example:

    if (md5($_POST['code']) == $_SESSION['__img_code__'])
        echo "Valid code";
    else
        echo "Invalid code";