jQuery AJAX Character Encoding

Specifying the content type on the AJAX-call solved my problems on a Norwegian site.

$.ajax({
        data: parameters,
        type: "POST",
        url: ajax_url,
        timeout: 20000,
        contentType: "application/x-www-form-urlencoded;charset=ISO-8859-15",
        dataType: 'json',
        success: callback
});

You would also have to specify the charset on the server.

<?php header('Content-Type: text/html; charset=ISO-8859-15'); ?>

UTF-8 is supposed to handle all accents and foreign chars - why not use it on your data source?

EDIT
[Archive copy of the test file.] with your data

Everything should be UTF-8 in the first place. I loaded the files in notepad++, converted to utf-8 and manually changed the charactes to accents were needed. Once done everything's working like a charm.

BTW, unless your server is defined to php-process .html files, the files you're loading with ajax aren't getting your iso charset. If you insist on using the iso charset, request a php file instead of an html file, and define the charset in the header (not in the file itself)

$str=iconv("windows-1250","UTF-8",$str);

what helped me on the eventually

You need to set up your server to use ISO-8859-15 as the character encoding (adding the appropriate HTTP header). Doing it in the body of the html won't help.

I can see this line

<?php header('Content-Type: text/html; charset=ISO-8859-15'); ?>

at the source of your html. This shouldn't happen. Using Live HTTP Headers I can't see the appropriate charset HTTP header. Use that for both your first page and the ajax service.