var last = 0;
function switchinfo(i) {
	var riga = document.getElementById('riga_'+i);
	var push = document.getElementById('push_'+i);

	if (riga != null) {
		if (riga.style.display == "block") {
			riga.style.display = "none";
			push.value = "+";
			last = 0;
		} else {
			riga.style.display = "block";
			if (i != last) {
				switchinfo(last);
			}
			last = i;
			push.value = "-";
		}
	}
}