Ajax tutorial FAQ

The Demos of the Ajax Tutorial (Asynchronous Javascript + XML) at https://www.xul.fr/en-xml-ajax.html work just fine. But when I download the zip-file and try to start the script, I keep getting an error-message at the bottom of the webpage. What did I do wrong? Do I need an extra file? Maybe a php-script?

Hello, The demo holds just ajax-get.html and a data file, no more file is needed (if it is demo.zip). The file works only online, because the statement if(req.status == 200) requires a server to work. If the file is uploaded on a server it should works, and through wamp too.