Creative Guestbook/Spam advice needed

[Roscoe]

Ok, here's the deal. I'm currently writing a Guestbook and I've noticed that the server it will be running on doesn't support the GD library to create graphics on the fly. I really wanted to use that to write one of those anti-automated-spam "please enter the code you see in the drawing" thingies. So, does anyone know of another good and practical system to keep those spambots at bay?

Thanks!

[mogster]

Hmmm...
What is "please enter the code you see in the drawing"-thingies? 😃

If that's the persons emailadress, this is a function to obfuscate email by javascript. I've written it into a php-function that takes two arguments: the email and the text for the mailto-link. Any non-js browsers (and the robots!) will get another syntax:

## We protect the email-addresses in the public scripts ##
function noSpam($email, $etext) {
$mArr = explode("@", $email);
if($etext != "") {
$mCode = "<script language=\"Javascript\">
<!--
a = \"".$mArr[0]."\";
b = \"".$mArr[1]."\";
document.write(\"<a href='mailto:\" + a + \"@\" + b + \"'>\");
document.write(\"".$etext."\");
document.write(\"</a>\");
//-->
</script>
<NOSCRIPT>".$mArr[0]." at ".$mArr[1]."</NOSCRIPT>";
} else {
$mCode = "<script language=\"Javascript\">
<!--
a = \"".$mArr[0]."\";
b = \"".$mArr[1]."\";
document.write(\"<a href='mailto:\" + a + \"@\" + b + \"'>\");
document.write(a + \"@\" + b);
document.write(\"</a>\");
//-->
</script>
<NOSCRIPT>".$mArr[0]." at ".$mArr[1]."</NOSCRIPT>";
}
return $mCode;
}

The javascript-enabled will get an ordinary mailto-link, the others will see:

<script language="Javascript">
<!--
a = "myemail";
b = "mydomain.com";
document.write("<a href='mailto:" + a + "@" + b + "'>");
document.write(a + "@" + b);
document.write("</a>");
//-->
</script>
<NOSCRIPT>myemail at mydomain.com</NOSCRIPT>

Not bulletproof, but it excludes the major bunch of robots that searches any page for "mailto:" and "@" for easy adding to their mailinglists.

knutm

[mogster]

Erm.. you call the function like this:

## Call with text for link ##
echo noSpam("[e-mail]", "Email the user");

## Call with mailadress for link ##
echo noSpam("[e-mail]");

knutm - FIGHT SPAM!!!! :o

[Roscoe]

Actually, I'm referring to those dynamically generated images that contain a combination of characters you have to copy into a text box. I think Hotmail asks you twice to copy such character string (it's called the "Registration Check"). Because people are (rightfully) afraid their e-mailaddress could be used for spam, I'm not going to make the e-mail field in this form mandatory. So I appreciate the code you put here 🙂 but it's not what I was thinking about.