var globalnav_switch = 0;	// switch to activate the dynamic navmenu

function show_dynamic_menu( openTabBar, SubNavID ) {
	// no action when switch is disabled
	if ( globalnav_switch == 0 ) {
		globalnav_switch = 1;
		return false;
	}

	var navmenu = document.getElementById('portal-globalnav');    // get the #portal-globalnav DOM
	var cnt_submenus = navmenu.getElementsByTagName('ul').length; // get the number of menus in #portal-globalnav
	
	var openSubBar = SubNavID + '-subnav';

	// foreach menu in #portal-globalnav
	for (var i = 0; i < cnt_submenus; i++) {
		currtab = navmenu.getElementsByTagName('ul')[i];
		currtabid = currtab.getAttribute('id');

		if ( (currtabid == openTabBar) || (currtabid == openSubBar) ) {
			// show current submenu
			document.getElementById('portal-globalnav').getElementsByTagName('ul')[i].style.display = 'block';
			
			if ( SubNavID != null ) {
				// change the class name of the submenu's parent anchor
				var SubNavParent = 'portaltab-' + SubNavID;
				document.getElementById( SubNavParent ).getElementsByTagName('a')[0].id = 'portaltab-openChildren';
				
			} else {
				// remove id from anchor if set
				openAnchor = document.getElementById('portaltab-openChildren');
				if (openAnchor) {
					openAnchor.removeAttribute('id');
				}
			}
			
		} else {
			// hide all other menus
			document.getElementById('portal-globalnav').getElementsByTagName('ul')[i].style.display = 'none';
		}
	}
	
	// disable the function when called with submenu-ID
	// prevents from recalling the function without the openSubBar parameter
	if ( SubNavID != null ) {
		globalnav_switch = 0;
	}

	return true;
}