function writeCookie(name, value, days){
	if(days){
		(time = new Date()).setTime(new Date().getTime()+days*24*60*60*1000);
		var exp = '; expires='+time.toGMTString();
	}else{
		var exp='';
	}
	document.cookie=name+"="+value+exp+"; path=/";
}

function readCookie(name){
	var cookies = document.cookie.split(';');
	for(var i=0; i < cookies.length; i++){
		var cookie=cookies[i].replace(/^\s+/, '');
		if (cookie.indexOf(name+'=')==0) {
			return cookie.substring(name.length+1);
		}
	}
	return null;
}

function eraseCookie(name){
	writeCookie(name, "", -1);
}

function addToCookie(value){
	var tmp = readCookie('HideID');
	if (tmp) {
		tmp+=value;
	} else {
		tmp=value;
	}
	writeCookie('HideID', tmp, 365);
}

function delFromCookie(value){
	var tmp = readCookie('HideID');
	tmp = tmp.replace(value,"");
	writeCookie('HideID', tmp, 365);
}

function HideGroups(){
	var ids=readCookie('HideID');
	if (ids) {
		var id = ids.split('$$');
		var imax = id.length-1;
		for (var i=0; i<imax; i++) {
			HideAntwoord(id[i]);
		}
	}
}

function HideAntwoord(nr)
{
	var elem = (document.getElementById) ? document.getElementById('antwoord' + nr) : ((document.all) ? document.all['antwoord' + nr] : null);
	if (elem) {
		document.getElementById('antwoord' + nr).style.display='none';
		document.getElementById('vraag' + nr).style.display='';
	}
}
function ShowAntwoord(nr)
{
	var elem = (document.getElementById) ? document.getElementById('antwoord' + nr) : ((document.all) ? document.all['antwoord' + nr] : null);
	if (elem) {
		document.getElementById('antwoord' + nr).style.display='';
		document.getElementById('vraag' + nr).style.display='none';
	}
}