If I may recommend not to use captchas... unless a really complex image generation technique is used, robots are more and more able to "read" captcha images.
The easiest way to prevent abuse of your HTML forms are these:
1. Ask a simply math question and depending upon the result, process the form or ask again. While this can be done by implementing some JavaScript, the PowerForm formmailer can do this as well using native functions.
2. The better solution is to simply have a multi-page form. On the second page, even no real use for you, you may ask people to verify their form entries and click on a button to proceed. This is quite effective, because any web robot I saw so far is unable to know what to do then (some even think that the form has been sent ;-)
PowerForm is also able to manage multi-page forms. You find more information about it here:
http://www.sunnyscript.com/PerlCGI/PowerForm/index.htm
06-22-2008, 05:44 PM
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