// JavaScript for banner menus

function setupBannerMenus() {
	var banner = document.getElementById('edition-banner');
	var menu = banner.getElementsByTagName('ol')[0];
	var items = menu.childNodes;
	for( i=0; i<items.length; i++ ) {
		addEvent(items[i],'mouseover',showSubMenu);
		addEvent(items[i],'mouseout',hideSubMenu);
	}
}

function showSubMenu(evt) {
	if (!evt) evt = window.evt;
	var li = findMenuItem(evt);
	var subMenu = li.getElementsByTagName('ol')[0];
	subMenu.style.display = 'block';
}

function hideSubMenu(evt) {
	if (!evt) evt = window.evt;
	var li = findMenuItem(evt);
	var subMenu = li.getElementsByTagName('ol')[0];
	subMenu.style.display = 'none';
}

function findMenuItem(evt) {
	if (evt.target) {
		// DOM compliant
		var node = evt.target; 
	}
	else {
		// IE/Win
		var node = evt.srcElement;
	}
	while (node) {
		if ( (node.nodeType == node.ELEMENT_NODE || node.nodeType == 1) && node.nodeName == "LI" ) {
			// node.ELEMENT_NODE does not seem to work in Safari
			return node;
		}
		node = node.parentNode;
	}
	return null;
}