function mainNavOver(id) {
	document.getElementById(id).className = "nav_button over";
	openSubMenu(id+'_sub');
}

function mainNavOut(id, section) {
	if (id=='mainNav_'+section) {
		document.getElementById(id).className = "nav_button selected";
	} else {
		document.getElementById(id).className = "nav_button";
	}
	closeSubMenu(id+'_sub');
}

function openSubMenu(id) {
	elem = document.getElementById(id);
	if(elem != null) {
		document.getElementById(id).style.display = "block";
	}
}

function closeSubMenu(id) {
	elem = document.getElementById(id);
	if(elem != null) {
		document.getElementById(id).style.display = "none";
	}
}

function subNavOver(id) {
	document.getElementById(id).className = "subOver";
}

function subNavOut(id) {
	document.getElementById(id).className = "noOver";
}