How simple is this?

[Teach]

Hi there.
Another query for you.

How can I include the "graphical" human input checks that many sites have? That creates randomly generated letters/numbers that then have to be entered, adn are validated, and if "correct" the form continues, and if not it won't.
I think this uses the GD PHP module, which my PHP configuration supports.
I'm using Apache 1.3.27, and PHP 4.3.2.

Thanks.

[pyro]

It wouldn't be overly hard, and if your lucky, there will be a class already written to do this.. If not, basically what will have to happen is this.

You will basically want to compair each image with a key. I would think the key would normally be included in a hidden form field, and the image/key comparisons in a database. When the form is submitted, query the DB with the image number that the user typed in, and the key from the hidden form field. If they match (not the same number, but mearly are the correct pair) you know that they entered the correct number.