How to create a Re-Captcha login on a site

hey guys, i am new to this forum, plz suggest me as to how can a create a small re-captcha validation on my site

What have you tried?
There is a comprehensive guide of how to do what you want here: https://developers.google.com/recaptcha/intro
Perhaps you can read this, then have a go at implementing what they suggest.
If you get stuck on a specific point then post back here.

This is a handy tool for setting that up: http://www.phpcaptcha.org/

Hoever, before rushing into Captcha—which kind of sucks for users—have a look at this thread:

It is worth considering a tripwire for bots that doesn’t hamper legitimate users, like a honeypot or a time check.

When I used ReCaptcha on a phpBB3 forum I got a lot of spam. I had to stop using it. I thought ReCaptcha had been cracked and apparently others do, too.

Yahoo - ReCaptcha Cracked

I am opened a site. please suggest me that how can i create a small re-captcha in my site.

Hi akonal78 - welcome to the forums. Have you read posts #2 and #3 above, which answer your question? If you’re stuck on some specific step, then please give more details so that we can help you.