Hi, all When you ask for a captcha, I'd first ask what do you want to use it for. If you read the first lines of Wikipedia it has been developed to differ between a real user and a bot. If you'd now say that you want to use it to protect spam in a formula I'd give you the same explanation that you can find here in german (in a bit more text): http://www.1ngo.de/web/captcha-spam.html The author of this link says that captchas are not efficient enough and give a new unnecessary barrier to all users. He also declaims that bots nowadays are better than ever and can even read captchas that many humans are not able to read. For this reason he provides a list of extra stuff that you can use to protect your formula against spam instead of a picture that's text should be written in an input-field. One of those is the honey-pot. You simply create an additional field (f.e. * email2*) hide it for most visitors (using *css*) and ignore the comment if there's text in here. As most of the bots cannot read css they'll fill a valid email-address in here :) But then you also have to think about users that have css disabled f.e. *ScreenReader*. Another disadvantage of this issue is that you can use an auto-field-fill mechanism provided by the browser who could fill this field ... But both cases should not be that difficult. For the screenreder you can change the label for the field to look like *Do not paste your email in here. Just leave it empty.* Just to have the word email again in here ;) Another good thing is to think about how fast this form can be submitted when the user enters the formula for the first time. Also think about the second time, when the user as entered some wrong values and you have to show him a message. If you have a formula that contains more than 5 fields it's quite unusual that the user can submit that below 2 sec after receiving the response. You could even add a feature by using javascript that the user cannot submit this form or his request will be delayed for a view seconds (one or two). If you want to know more about that, out there are plenty of plugins for different systems where you can see what other possibilities you have. One extension i like is the one from TYPO3. They have quite a bunch of such things and you can give each of the checks a value. If the sum of the values of the failing tests reaches a configured level, this form-submission will be rejected. http://typo3.org/extensions/repository/view/wt_spamshield/current/ Wordpress: http://antispambee.de/ Bye Simon 2012/2/17 Savetheinternet <savetheinternet@xxxxxxxxxxxxx> > On Fri, Feb 17, 2012 at 3:40 PM, Donovan Brooke <lists@xxxxxxx> wrote: > > Hello, > > > > Does anyone know of a basic (open source or freeware) form captcha system > > for PHP? > > > > TIA, > > Donovan > > > > > > > > > > -- > > D Brooke > > > > Hi, > > There are plenty of free PHP captcha scripts out there. Just google > "captcha PHP". Securimage (phpcaptcha.org) looks relatively okay. > > Thanks, > Michael > > -- > PHP General Mailing List (http://www.php.net/) > To unsubscribe, visit: http://www.php.net/unsub.php > >
