How to improve this Contact Form?

PHP
1

This contact form works fairly well, but I do get spam.

Can you add something to this existing form that will make it a little better at not letting spam thru?

<form action="../page.php?page=1" method="post" name="contact_us" onSubmit="return capCheck(this);">
<table cellpadding="5" width="100%">
<tr>
<td width="10" class="required_field">*</td>
<td width="80">Name</td>
<td><input type="text" name="name" maxlength="50" style="width:400px; border: 1px solid #696969;" /><br /><br /></td>
</tr>
<tr>
<td class="required_field">*</td>
<td>Email Address</td>
<td><input type="text" name="email" maxlength="40" style="width:400px; border: 1px solid #696969;" /><br /><br /></td>
</tr>
<tr>
<td></td>
<td>Subject:</td>
<td><input type="text" name="subject" maxlength="40" style="width:400px; border: 1px solid #696969;"/><br /><br /></td>
</tr>
<tr>
<td class="required_field">*</td>
<td>Enter Image Code:</td>
<td><input type="text" value="" name="captext" style="width: 100px" maxlength="6" /></td>
</tr>
<tr>
<td></td>
<td><a onclick="refresh_security_image(); return false;" style="cursor:pointer;"><u>Refresh Image</u></a></td>
<td><img src="../includes/captcha.php" border="0" id="verificiation_image" /></a></td>
</tr>
</table>
<br/>
<p>
<input type="hidden" name="submited" value="1" />
<input type="submit" name="submit" value="Submit" style="margin:7px 10px 0px 0px; padding:10px 0px 10px 0px; font-size:15px; font-style:Century-Gothic;" />
</p>
</form>
</td>
</tr>
</table>
</div>
<script type="text/javascript">
<!--
function refresh_security_image() {

var new_url = new String("../includes/captcha.php?width=132&amp;height=36&charcators=");
new_url = new_url.substr(0, new_url.indexOf("width=") + 37);
// we need a random new url so this refreshes
var chr_str = "123456789";
for(var i=0; i < 6; i++)
new_url = new_url + chr_str.substr(Math.floor(Math.random() * 2), 1);
document.getElementById("verificiation_image").src = new_url;
}
-->
</script>

<!-- captch start -->
<script type="text/javascript" id="clientEventHandlersJS" language="javascript">
</script>
<!-- captch end -->

Thanks

2

Is that link to produce the captcha image correct? I’m thinking of the bit that says “charcators” where I’d have expected it to say “characters” or “charactors”, and “verificiation_image”. Might be nothing, of course whoever authored that function can use whatever parameter names they like, and I guess that bit wouldn’t work at all if they were really incorrect.

Other than that, though, you have to balance out making it impossible for spammers but still usable for normal people. I have no contact details on my web site, just a form with a few boxes and a note that says “if you’re offering to boost by web position, number of followers or size of anything, don’t waste your time” and I still get people who spend time filling out the form and sending this junk in.

Also as the code isn’t PHP, you might get a better response in a more appropriate section of the forum.

3

Presumably there’s a PHP script that sends the form, and that’s where the spam filtering should be. JS spam filtering isn’t worth much, as it can be turned off.