function show_types (id) {

	var obj = document.getElementById(id);

	if (obj && obj.style.visibility == 'hidden') {
		obj.style.position = 'static';
		obj.style.visibility = 'visible';
		}
	else if (obj && obj.style.visibility == 'visible') {
		obj.style.position = 'absolute';
		obj.style.visibility = 'hidden';
		}

	}