A simple trick to help prevent form spam (2)
This is a more sophisticated setup of this blog comment spam prevention tactic. I've implemented this several weeks ago and it seems to work well.
- After changing the URL of your blog's comment executable, encode the new URL here. For this, enter your URL where indicted "Step 1: enter your e-mail address". Copy the code given to you and extract the strings string1 and string2, which look respectively like FPZEVPKWZXDS2M and %27%23%3E%237%23/1%3C7+1S%3F.
- Place the following code after the <head> tag of the page, after replacing string1 and string2 by their actual values:
<script type='text/javascript'><!-- function blurl(){var v2="string1";var v7=unescape("string2"); var v5=v2.length;var v1="";for(var v4=0;v4<v5;v4++) {v1+=String.fromCharCode(v2.charCodeAt(v4)^v7.charCodeAt(v4));}return v1} //--></script> - Locate the comment form in the template of your blog, and remove the action attribute specifying the URL of the executable used to process the form results.
- Finally, add this.action=blurl() to the onsubmit handler of the form:
<form method="post" onsubmit="this.action=blurl()"> ... </form>
Updates: There is an updated version of this document, and you can now get free comment spam protection with FormSmarts.