I've seen it on various websites (www.logitech.com just for one), and I'm trying to duplicate the code for myself: how can I have a generated HTML form change its own input fields (dropdown menus, etc) based on the values of other input fields in the same form? I assume there will be a JavaScript function to reload the page with the current values intact, and make sure the .cgi (or .pl, whatever) that creates the form has a logic tree to check which input fields need to be displayed? Does anybody have a small snippet to get me started on that?