function topnav_init(menuId) {
	curPage = '';
	curMenu = '';
	mainimg = document.getElementById('img');
	var menu = document.getElementById(menuId);
	var menuItems = menu.getElementsByTagName('li');
	var bodyClasses = document.getElementsByTagName('body')[0].className;
	bodyClasses = bodyClasses.split(' ');

	for (var i=0; i<menuItems.length; i++) {
		if (menuItems[i].className.match(/\btopmenu\b/)) {
			//alert('setting submenu for ' + menuItems[i].id);
			menuItems[i].submenu = menuItems[i].getElementsByTagName('ul').item(0);
		}
		menuItems[i].onmouseover = nav_over;
		menuItems[i].onmouseout = nav_out;
		menuItems[i].getElementsByTagName('a')[0].onclick = nav_click;

		// set the current page so that it reappears onmouseout
		if (menuItems[i].id == bodyClasses[0]) {
			//alert('setting ' + menuItems[i].id + ' as current menu');
			menuItems[i].getElementsByTagName('a')[0].style.backgroundColor = '#F7F9F4';
			curPage = menuItems[i].id;
			curMenu = menuItems[i].submenu;
		}
	}
}

function nav_over () {
	if (curMenu) {
		//alert('hiding current submenu');
		curMenu.style.visibility = 'hidden';
	}
	if (!this.submenu) return;

	this.submenu.style.visibility = 'visible';
	curMenu = this.submenu;
}

function nav_out () {
	if (this.submenu) {
		this.submenu.style.visibility = 'hidden';
		curMenu = '';
	}
	if (curPage) {
		//alert('revealing ' + curPage + ' menu');
		var page = document.getElementById(curPage);
		page.onmouseover();
	}
}

function nav_click () {
	this.blur();
	// follow link unless there's a submenu
	if (!this.parentNode.submenu) return true;

	//alert ('found submenu for ' + this.id);

	return false;
}