var activeMenu = '';	
function showSubMenu(n){
	//closeAllSubMenu();
	activeMenu = n;
	document.getElementById('menu_'+n).style.display = 'block';
	}
	
function closeSubMenu(n){
	activeMenu = '';
	document.getElementById('menu_'+n).style.display = 'none';
	}

function closeAllSubMenu(){
	activeMenu = '';
	document.getElementById('menu_verhuur').style.display = 'none';
	}