var current = 'subBrowseCollection';

function showSubNav(navId) {
	var reveal = document.getElementById(navId);
    reveal.style.display = "block";
	if (current != navId) {
		var hide = document.getElementById(current);
		hide.style.display = "none";
		current = navId;
	}
}
function hideSubNav() {
	var hide = document.getElementById(current);
    hide.style.display = "none";
}