It means that whatever server the /CGI-BIN/shop.pl is on won't accept return data to the script in the POST format. There are two CGI methods used for a form in a browser to send return information: GET and POST . This script, the server it is sitting on or the browser form associated with its activation aren't using the correct method or the correct formatting for the parameters. Try looking at the CGI stuff on http://www.thesitewizard.com
for answers. They usually have straight dope available from the links there. Good luck. And for future reference, I'd think that this would fit more into the Web Programming section.