function ChangeNow(welke,aantal){
	if(document.getElementById){
		for(var i=1;i<=aantal;i++){
			document.getElementById('sub'+i).style.visibility = 'hidden';
			document.getElementById('sub'+i).style.display = 'none';
			document.getElementById('img'+i).src='../images/pijl_grijs.gif';
		}
		document.getElementById('sub'+welke).style.visibility = 'visible';
		document.getElementById('sub'+welke).style.display = 'block';
		document.getElementById('img'+welke).src='../images/pijl_rood.gif';
	}
}
function PlusMinSH(nr){
	elm = document.getElementById('plusmin'+nr).style;
	if(elm.visibility == 'visible'){
		elm.visibility = 'hidden';
		elm.display = 'none';
	}else{
		elm.visibility = 'visible';
		elm.display = 'block';
	}
}