function setDisplayAll(val, id) {
	var n = 1;
	while(document.getElementById(id+"-"+n) != null) {
		document.getElementById(id+"-"+n).style.display = val;
		document.getElementById('ce-img-'+n).src = (val == 'none' ? 'http://www.skatemap.it/images/icon-16-expand.gif' : 'http://www.skatemap.it/images/icon-16-collapse.gif');
		n++;
	}
}