Asirra — Installation Instructions
Protecting your web site with Asirra is easy. It just takes a few lines of code in whatever language your web service is written in. See these complete working examples:
There are four basic steps, described below. First, add a call to our JavaScript from your web form. Second, wire your "submit" button to our Asirra validation function. Third, write your own JavaScript function that submits the form once you get a callback saying the Asirra challenge has been successfully solved. Finally, add a call to our web service from your server form processor, to ensure that you are not getting a request from a cheating client.