function MM_findObj(n, d) { //v4.01
  var p,i,x;  if(!d) d=document; if((p=n.indexOf("?"))>0&&parent.frames.length) {
    d=parent.frames[n.substring(p+1)].document; n=n.substring(0,p);}
  if(!(x=d[n])&&d.all) x=d.all[n]; for (i=0;!x&&i<d.forms.length;i++) x=d.forms[i][n];
  for(i=0;!x&&d.layers&&i<d.layers.length;i++) x=MM_findObj(n,d.layers[i].document);
  if(!x && d.getElementById) x=d.getElementById(n); return x;
}

function openSubMenu(obj) {
	closeAllSubMenus(obj);
	var parent = obj.parentNode;
	for ( var x = 0; x < parent.childNodes.length; x++) {
		if ( parent.childNodes[x].nodeName == 'UL' ) {
			parent.childNodes[x].style.display = 'block';
		}
	}
}

function closeSubMenu(obj) {
	var parent = obj.parentNode;
	for ( var x = 0; x < parent.childNodes.length; x++) {
		if ( parent.childNodes[x].nodeName == 'UL' ) {
			parent.childNodes[x].style.display = 'none';
		}
	}
}

function closeAllSubMenus(obj) {
	var parent = obj.parentNode.parentNode;
	for ( var x = 0; x < parent.childNodes.length; x++) {
		if ( parent.childNodes[x].nodeName == 'LI' && parent.childNodes[x].childNodes.length > 1 ) {
			closeSubMenu(parent.childNodes[x].childNodes[0]);
		}
	}
}

var cursubmenu =  '';

function flipSubMenu(id) {
	if ( id != 'actueelsub' && cursubmenu != 'actueelsub') closeSubMenu('actueelsub');
	if ( id != 'wiezijnwesub' && cursubmenu != 'wiezijnwesub') closeSubMenu('wiezijnwesub');
	if ( id != 'trainingensub' && cursubmenu != 'trainingensub') closeSubMenu('trainingensub');
	if ( id != 'prikbordsub' && cursubmenu != 'prikbordsub') closeSubMenu('prikbordsub');
	if ( cursubmenu != id ) {
		var obj = MM_findObj(id);
		if ( obj.style.display ==  'none' )
			openSubMenu(id);
		else
			closeSubMenu(id);
	}
}