Stopping comment spam

I run a website http://www.article-gems.com and have my comments spams by a viagra robot - 10-25 comments a day all from different sites (I think it uses these others sites like a virus would).

Any suggestions how I can stop this without having to delete 20 plus comments a day?

 

add image verification

 

thanks for your response, any suggestion where I can get the script and how do I install it?

 

hmmm... You can make a very very simple one and keep changing it everytime if it continues:

1. make 5-10 images (named check1.gif check2.gif etc...)
2. pick random integer 1-10.
3. echo image...
4. echo a hidden input with the value of the image.., and ask forthe verification.
5. get hidden input and match it with the verification.

if you have very, very basic php that should be good. maybe make more images and make it more complex later on. A person who codes spam bots would be able to get around this, but I don't think people who do this code for specific sites. they just get a huge list of urls and run the bot like theres no tomorrow, soyou should be safe with this method.

 

there are a couple of free captcha scripts that are open source flying around..it would help you though.

 

ya captcha is the norm for most spam protection including comments, form submissions, image uploads, etc.

Plenty of free ones circulating.