var ajax = new Drupal.ajax(false, '#start-page-filter-save', {
event: 'click',
url: "start_page_ajax_filter_save",
progress: {
'type': 'none'
}
});
// To add data to POST:
ajax.options.data = form.serializeArray();
// To send any time we need - just call:
ajax.eventResponse(ajax, {});