var checkflag = "false";

function checkAll(field) {

	if (checkflag == "false") {
		check(document.getElementById(field.name).getElementsByTagName('input'), true);
		checkflag = "true";
	}else {
		check(document.getElementById(field.name).getElementsByTagName('input'), false);
		checkflag = "false";
	}
}

function check(field, what) {
	for (i = 0; i < field.length; i++) {
		field[i].checked = what; 
	}
}

function showList(list) {

	document.getElementsByClassName('info').each(
		function(element){ 
			element.style.height = "0px";
			check(document.getElementById(element.id).getElementsByTagName('input'), false);
		}
	);
	
	if (document.getElementById(list)) {
		document.getElementById(list).style.height = "";
		check(document.getElementById(list).getElementsByTagName('input'), true);
	}
}

// to do: check of minimaal 1 cat. geselecteerd is