Javascript to change the list of states when a country changes

change_states_for_country.html

<script type="text/javascript">
    // Workaround to change the value of `State` select options from `CC+XX` to the
    // state name.  Bogus values will not show up in supporter records -- A Good Thing.
    //
    // @note  The Salsa-provided `change` event handler is unbound by this code.  It's
    //        the one that plants bogus values in the `State` select options, and doesn't
    //        need to run.  To make this happen correctly, this script must appear *just before*
    //        the </body> tag in your template.
    //
    // @see https://help.salsalabs.com/entries/23796550
    //
    // @dependencies jQuery, any version
    //
    $(document).ready(function() {
        //  This script only runs if there is a Country field on the page.
        var country = $('select[name=Country]');
        if (country.length == 0) return;
        if ($('select[name=State]').length == 0) return;
        var organizationKey = $('*[name=organization_KEY]').val();

        country.unbind('change');
        country.change(function() {
            var countryCode = $('select[name=Country]').val();
            if (countryCode == null || countryCode.trim().length == 0) {
                return;
            };
            $("select[name=State]").empty();
            var url = "/o/" + organizationKey + "/p/salsa/common/international/public/country/eng/countryData.sjs?country=" + countryCode + "&jsoncallback=?"
            $.getJSON(url, function(data) {
                $("select[name=State]").append("<option value>Select a state or province</option>");
                data.states.map(function(state) {
                    // Note that the name won't replace the code for US states because
                    // none of the official state abbreviations have numbers.
                    if (RegExp('\\d+').test(state.code)) {
                        state.code = state.name;
                    }
                    $("select[name=State]").append("<option value='" + state.code + "'>" + state.name + "</option>");
                    return state;
                });
            });
        });
        // Set the default country code to the United States (US).
        $("select[name='Country']").val('US').change();
        // Make the state prompt less US-centric.
        $('*[name=State] option:first').text('Select a state or province');
    });
</script>