Congratulations on your successful form submission!
In this example, the form was processed by "process.php" (this file). If you entered the captcha code incorrectly, you were redirected back to the form page (index.php) with an error message displayed under the captcha. Whatever the user entered into the form fields was left in tact. Since you entered the code correctly, the contents of "process.php" are now being displayed.
Another option would be to redirect the user to "index.php?msg=captchasuccess" and have "index.php" show different data on the screen if it receives "captchasuccess" for "$_GET['msg']". In other words, captcha_lite also works for self-submitting forms.