I have a site that allows webmasters to create a poll for their site. One of the features of my polls is preventing users from voting twice. I do this by recording the IP addresses. But I'm receiving many requests from users behind a firewall to prevent users from voting twice by using cookies instead of checking the IP address. Users behind a firewall have the same IP address.
I know my CGI, but I have no idea how to do this with cookies. Can someone tell me where I can get more information about this subject?
cookies are risky as well, because of that they can disable their cookies and oppss your poll is being voted by the same person several times.
By saying CGI you mean perl? then you should check www.perl.com you can find documentation there easily.