If you have a multilingual website, here's a very simple Javascript to switch languages on your site. Assume I have two websites with the same structure, same filenames and so on, but the paths are either /en/ or /jp/ - for English or Japanese respectively. I want a button on the page that switches languages, to the other equivalent page.

Here is one way - the code below between the HTML p tags is all on one line. Ugly but it works. I imagine there is a better way to write the regexp since this one makes assumptions that there is only one "-en" substring in the URL. This code would be placed on the English site, and could be used to switch to Japanese.

<p>Change to <a href="javascript:var thisurl = unescape(document.URL);var targurl = thisurl.replace(/-en/gi,'-jp');location.href=targurl;">Japanese</a></p>