var ns4 = (document.layers)? true:false;
var ie4 = ((document.all) && (!document.getElementById))? true:false;
var ns6 = ((document.getElementById) && (!ie4))? true:false;

function hideAllMenus() {
	var submenu_id = ['subnavBooks', 'subnavEvents', 'subnavCourse'];
	var menu_nm = ['menuBooks', 'menuEvents', 'menuCourse'];

	for (var i=0; (i<menu_nm.length);i++)
		document.getElementById(menu_nm[i]).className='inactiveMenuItem';

	for (var i=0; (i<submenu_id.length); i++)
		subnavItem=document.getElementById(submenu_id[i]).className='inactiveSubMenu';
}

function showMenu(menu_nm, submenu_id) {
	document.getElementById(menu_nm).className='activeMenuItem';
	document.getElementById(submenu_id).className='activeSubMenu';
}