I REALLY NEED THIS!

My site is being hit by spammers that complete my forms with their junk and I want to block their IP address.

In other posts, I'm told "it's easy, just google a bit of PHP or Javascript".

Please. If it is that easy, just give me a bit of code I can plug in?

If it makes it easier, just tell me how I can map their IP address to say, the Fax number field?

Thanks!

Ian