function showSubnav(id) {
	hideAllSubnav();
	subnav = document.getElementById(id);
	subnav.style.display = 'block';
}

function hideAllSubnav() {
	document.getElementById('subnavigatieHistorie').style.display = 'none';
	document.getElementById('subnavigatieArr').style.display = 'none';
	document.getElementById('subnavigatieOrganisatie').style.display = 'none';
	document.getElementById('subnavigatieComite').style.display = 'none';
	document.getElementById('subnavigatieMedia').style.display = 'none';
}