UNI Webtools: Resources for Web Developers

Captcha Forms

What it is

Many online forms at UNI and elsewhere get large amounts of spam. One fairly straight forward method of defeating this problem is to implement a Captcha. Captcha stands for Completely Automated Public Turing test to tell Computers and Humans Apart. A captcha is simply an image of a word or a series of characters, often skewed and with distractions to make them possible for humans to read but hard or impossible for bots to defeat. Captchas are easy and cheap, but do come with several disadvantages, the main being some accessibility issues.

How it's used

1. Set up the page like one normally would for a Soupermail.
2. The form should post to "/webtools/captcha/check-captcha.cgi".
IE: <form method="post" action="/webtools/captcha/check-captcha.cgi">
3. You may have to change the SoupermailConf filed to provide the loctaion relative to the root.
IE: <input type="hidden" name="SoupermainConf" value="yourConfig.con" />
4. An additional hidden filed must be used. This field should be named SoupermailAddress and have as a value the http:// location of the Soupermail script you're using.
IE: <input type="hidden" name="PostAddress" value="http://www.uni.edu/cgi-bin/uniforms.cgi" />
5. Use server side includes to get the image and text box. (remove the space between !-- and #)
IE: <!-- #include virtual="/webtools/captcha/includes.cgi" -->

• All files are located in /webtools/captcha.
• Works with Soupermail on files located under uni.edu
• Form input identifiers (name, id) must be all one word: no spaces.

Maintained by University Marketing & Public Relations
Last Modified: Monday, 05-Nov-2007 16:38:35 CST