Captcha Script

I need a captcha script that will prevent users from registering if the code entered is incorrect. The script is already done it just needs to be installed. You can examine the code here.

http://www.abeautifulsite.net/blog/2011/01/a-simple-php-captcha-script/

I need it to be implemented into my registration script. I already have a working registration script as well as a database.