captcha code?

I want captcha code for my site with refresh image?
Any idea?

 

There are lot of free scripts available which you can integrate into your site e.g. http://captcha.net/

 

too many scripts are available there on internet, you may follow "skzubair" link too.

 

i want script not integrate code. i need, create a code in my site not just give link my site.
For example: http://www.transportrankings.com/sign-up.php

 

Yes thats what i meant, check my site http://www.psdtoxhtmlcss.com/contacts.php?p=4