var menuCount = 2;
var currentMenu = 0;

var navMenuName = "nav";
var dropMenuName = "menu";
var menuItemName = "item";

function isNavMenu(ID) {
	if (ID) {
		return (ID.indexOf(navMenuName) == 0 && parseInt(ID.substr(navMenuName.length)) > 0) ? true : false;
	} else {
		return false;
	}
}

function isDropMenu(ID) {
	if (ID) {
		return (ID.indexOf(dropMenuName) == 0 && parseInt(ID.substr(dropMenuName.length)) > 0) ? true : false;
	} else {
		return false;
	}
}

function isMenuItem(ID) {
	if (ID) {
		return (isDropMenu(ID) && ID.indexOf(menuItemName) > 0) ? true : false;
	} else {
		return false;
	}
}

function init() {
	var objNav = null;
	var objMenu = null;

	for (var i = 1; i <= menuCount; i++) {
		objNav = document.getElementById(navMenuName + i);
		objMenu = document.getElementById(dropMenuName + i);

		if (objNav.attachEvent) {
			objNav.attachEvent("onmouseover", showMenu);
			objNav.attachEvent("onmouseout", hideMenu);
			objMenu.attachEvent("onmouseout", hideMenu);
		} else
		if (objNav.addEventListener) {
			objNav.addEventListener("mouseover", showMenu, true);
			objNav.addEventListener("mouseout", hideMenu, true);
			objMenu.addEventListener("mouseout", hideMenu, true);
		} else {
			objNav.onmouseover = showMenu;
			objNav.onmouseout = hideMenu;
			objMenu.onmouseout = hideMenu;
		}

		objMenu.style.visibility = "hidden";
	}
}

function showMenu(evt) {
	evt = evt ? evt : (window.event ? window.event : null);

	if (evt) {
		var evtTarget = evt.target ? evt.target : evt.srcElement;
		var num = parseInt(evtTarget.id.substr(navMenuName.length));

		var objNav = null;
		var objMenu = null;

		for (i = 1; i <= menuCount; i++) {
			if (i != num) {
				objNav = document.getElementById(navMenuName + i);
				objMenu = document.getElementById(dropMenuName + i);

				objMenu.style.visibility = "hidden";
			}
		}

		if (num != currentMenu) {
			currentMenu = num;

			objNav = document.getElementById(navMenuName + num);
			objMenu = document.getElementById(dropMenuName + num);

			if (objNav && objMenu) {

				with (objMenu.style) {
					visibility = "visible";
				}
			}
		}
	}
}

function hideMenu(evt) {
	evt = evt ? evt : (window.event ? window.event : null);

	if (evt) {
		var evtFrom = evt.target ? evt.target : evt.srcElement;
		var evtTo = evt.relatedTarget ? evt.relatedTarget : evt.toElement;
		var num = parseInt((evtFrom.id.indexOf(navMenuName) == 0) ? evtFrom.id.substr(navMenuName.length) : evtFrom.id.substr(dropMenuName.length))

		if (!(isNavMenu(evtFrom.id) && isDropMenu(evtTo.id)) && // not moving from navMenu to dropMenu and
			!(isDropMenu(evtFrom.id) && isNavMenu(evtTo.id)) && // not moving from dropMenu to navMenu and
			!(isDropMenu(evtFrom.id) && isMenuItem(evtTo.id)) && // not moving from dropMenu to menuItem and
			!(isMenuItem(evtFrom.id) && isDropMenu(evtTo.id)) // not moving from menuItem to dropMenu
			) {
			currentMenu = 0;

			var objMenu = document.getElementById(dropMenuName + num);

			objMenu.style.visibility = "hidden";
		}
	}
}