Blocking spam from a comment-section

Question

I want to include something in my code to avoid spam in my
sql-driven comments-section of my website.
I posted this already in another thread but since it was
marked as solved, nobody responded to my question. I tried to use
the following method suggested by Joe Makowiec in this forum:
Originally posted by:
Newsgroup User
In foil.js:
// JavaScript Document
document.write("<input name='foil'
type='hidden' value='orange' />");
and in the mail form:
script language="JavaScript"
src="foil.js"
type="text/JavaScript"></script>
noscript
tr>
td>Enter 'orange' here:</td>
td><input name='foil'
/></td>
/tr
> </noscript>
I also put in the corresponding php as suggested:
?php
if ($_POST['foil'] == 'vrede') {
// Have field 'foil' with correct value
// Do other processing here
} else {
// Field 'foil' is missing or blank
// Odds on we have a bot
// Do something other than sending the mail
sorry that I didn't put this into the code-attachment but I
didn't want anybody to confuse this with my coding. If you'd like
to see the original coding, here you can have a look:
the
original discussion
However, it doesn't work. And what is worst: the same error
happens that I occurred when I tried to include a captcha! It
simply posts the spam comments anyway (with or without the right
code word).
I am not particularly good at php coding yet and quite
frankly, deciding where to put in a code fragment is pretty much a
guessing game for me. Maybe someone can see what the problem is if
I give you the coding I have done so far.:

Answer 1

the thing is not that I don't want to use captchas, it is
just that it doesn't work. Also I think that registering scares
people off. There MUST be a way how to do this. However, I have
been trying to find one for almost 5 days now and I always end up
with the same result (confer above). Does any body see where the
code-error lies?