< CAPTCHA < Integration 
  
      This is a CAPTCHA killer. It needs nothing on the form except a hidden field and some server-side code.
PHP Example
//... Your lovely form here
// Example, please adapt
echo "<input type=hidden name=url />";
//... Rest of your lovely form here
verification
// compare
if ($_POST['url'] != "") {
 // abort!
}
// processing code here
See also
    This article is issued from Wikibooks. The text is licensed under Creative Commons - Attribution - Sharealike. Additional terms may apply for the media files.