function init() {
	toggle_sub('sub3', false);
	toggle_sub('sub13', false);
	toggle_sub('sub27', false);
}

function toggle_sub(id, enabled) {
	var sub = document.getElementById(id);
	if (sub) {
		sub.className = enabled ? '' : 'disabled';
		var elements = sub.getElementsByTagName('input');
		for (var i=0; i<elements.length; i++) {
			var element = elements[i];
			element.disabled = !enabled;
			if (element.type == 'text') {
				element.value = ''
			} else if (element.type == 'radio') {
				elements[i].checked = false;
			}
		}
	}
}

function validate_form() {
	var elements = document.getElementsByTagName('input');
	for (var i=0; i<elements.length; i++) {
		var element = elements[i];
		if ((element.type == 'radio') && (!element.disabled)) {
			if ((!obj) || (obj.name != element.name)) {
				if (val == 0) {
					commit_error(obj);
					return false;
				}
				var obj = element;
				var val = 0;
			}
			if (element.checked) {
				val = element.value;
			}
		}
	}
	if (val == 0) {
		commit_error(obj);
	}
	return true;
}

function commit_error(obj) {
	if (obj) {
		alert('Veuillez répondre à la question #'+obj.id.replace(/\D/g,''));
		obj.focus();
	}
}