Plugin: Hidden Input
Author: Mark Wu
Release Date: 2005/03/13
Version: 1.2

This plugin offers you add hidden fields to your comment form to prevent comment spam robot. Usage as followed:

Configuration:
1. Create a number of hidden fields in the configuration settings.

2. Put some of them in the "empty" list.  That way, some of the fields
   will have to be filled in, and some left blank, it will be harder
   for the spammer to figure it out.

You can use:
1. $hiddeninput->printHiddenFields() to print out the hidden fields

Example:
Add the following code to commentform.template inside <form> ... </form>:
{if $hiddeninput}
  {$hiddeninput->printHiddenFields()}
{/if}


IMPORTANT CHANGE in 1.2:
  Use printHiddenFields() to print the HTML rather than doing it
   yourself.  Also, see the new EmptyField setting to confuse the
   spammers a little more.