function accordion(el) {
    if ($('visible') == el) {
        return;
    }
    if ($('visible')) {
        var eldown = el.parentNode.id+'-body';
        var elup = $('visible').parentNode.id+'-body';
        new Effect.Parallel(
        [
            new Effect.SlideUp(elup),
            new Effect.SlideDown(eldown)
        ], {
            duration: 0.2
        });
        $('visible').id = '';
    } else {
        var eldown = el.parentNode.id+'-body';
		new Effect.SlideDown(eldown, {duration: 0.2});
	}
    el.id = 'visible';
}

function init() {

    // hide all elements apart from the one with id identified by vis
    var acc = seleziona('accordion');
    var apanels = acc.getElementsByTagName('div');
    for (i = 0; i < apanels.length; i++) {
        if (apanels[i].className == 'panel_body') {
            apanels[i].style.display = 'none';
        }
    }
    var vis = seleziona('visible');
    if (vis) {
	    var avis = vis.parentNode.id+'-body';
    	seleziona(avis).style.display = 'block';
	}
}
function addEvent(elm, evType, fn, useCapture) {
    elm["on"+evType]=fn;return;
}