Anti-spam for website forms

[jcdesigns]

How can I create a anti-spam feature on a website form where you will have to enter letters or numbers like a image. Click on link and scroll to the bottom for example. Thanks

http://www.pageprogressive.com/modules/contact/?form_id=1

[fastsol1]

It's called a captcha. PHP is the most used technique for this. You can get the most recognized version from the official captcha site http://www.captcha.net/

[jcdesigns]

Thanks