不灭的火

cool-php-captcha下载地址：

http://code.google.com/p/cool-php-captcha/downloads/list

cool-php-captcha具体效果：

cool-php-captcha代码实例：

session_start();
$captcha = new SimpleCaptcha(); 

// OPTIONAL Change configuration...
// $captcha->wordsFile = 'words/es.php';
// $captcha->session_var = 'secretword';
// $captcha->imageFormat = 'png';
// $captcha->scale = 3; $captcha->blur = true;
//$captcha->resourcesPath = "/var/cool-php-captcha/resources";
// OPTIONAL Simple autodetect language example
/*
if (!empty($_SERVER['HTTP_ACCEPT_LANGUAGE'])) {
	$langs = array('en', 'es');
	$lang  = substr($_SERVER['HTTP_ACCEPT_LANGUAGE'], 0, 2);
	if (in_array($lang, $langs)) {
		$captcha->wordsFile = "words/$lang.php";
	}
}
*/
// Image generation
$captcha->CreateImage();

输出图片：

验证码校对：

if (empty($_SESSION['captcha']) || strtolower(trim($_REQUEST['captcha'])) != $_SESSION['captcha']) {
	return "Invalid captcha";
}