Filter for Random/Possibly Malicious Submissions

[djr33]

Aside from actually doing it for you, it's difficult to explain if you don't have that background. However, ReCAPTCHA is very popular so you should be able to look up a tutorial-- maybe try youtube for a video tutorial.
And if that doesn't work, I'm certain you can find a very detailed tutorial on another CAPTCHA. For your current situation, there won't be a big difference from one to another, just whatever is easiest to set up.

[WorldWiz]

Cool. I've got the captcha working based on a youtube tutorial, so now my last question is, how do I code the texts ("captcha accepted" and "captcha not accepted") to appear as pop-ups instead of as text at the top of the page?

[djr33]

You'd have to edit the recaptcha code to do that, and I'm not sure exactly how/where you'd do it. It shouldn't be too hard, honestly-- just replace them with script tags and alert() code, but it might be hard to find it and to make them work properly. If you have trouble, 1) see if anyone has tried something similar; or 2) you might want to look into another captcha script that is more customizable or easier to modify-- or just leave it as is.