var isNav = (navigator.appName.indexOf("Netscape") != -1);
var isIE = (navigator.appName.indexOf("Microsoft") != -1);
var cid = null;
var cpath = "";
var urlPrefix = "";

//TAG_ID_OF_IMG, HIGH_LIGHT_IMG, NORMAL_IMG
var menuData = [
	['nav_index', 'btn_home.jpg', 'btn_home2.jpg', 'ROOT_PATH_SHOULD_NOT_CONTAIN_ANYTHING'],
	['nav_about', 'btn_about.jpg', 'btn_about2.jpg', 'aboutus'],
	['nav_organization', 'btn_organization.jpg', 'btn_organization2.jpg', 'organization'],
	['nav_getinvolved', 'btn_getinvolved.jpg', 'btn_getinvolved2.jpg', 'getinvolved'],
	['nav_contactus', 'btn_contactus.jpg', 'btn_contactus2.jpg', 'contactus'],
	['nav_meetings', 'btn_meetings.jpg', 'btn_meetings2.jpg', 'meetings'],
	['nav_projects', 'btn_projects.jpg', 'btn_projects2.jpg', 'projects'],
	['nav_publications', 'btn_publications.jpg', 'btn_publications2.jpg', 'publications'],
	['nav_pressroom', 'btn_pressroom.jpg', 'btn_pressroom2.jpg', 'pressroom']
]


function findElem(ename) {
	for(var i = 0; i < menuData.length; i++) {
		rarry = menuData[i];
		if(ename == rarry[0]) {
			return rarry;
		}
	}
}

function getTargetElem(e) {
	if(isNav) {
		return e.target;
	}
		
	if(isIE) {
		e = window.event;
		return e.srcElement;
	}
}

function mouseOverHandler(e) {
	targetElem = getTargetElem(e);
	foundArry = findElem(targetElem.id);
	targetElem.src = urlPrefix + "/" + foundArry[1];
	
}

function mouseOutHandler(e) {
	targetElement = getTargetElem(e);
	foundArry = findElem(targetElem.id);
	
	if(cid == targetElem.id || (cpath.toLowerCase().indexOf(foundArry[3].toLowerCase()) > 0) ) {
		targetElem.src = urlPrefix + "/" + foundArry[1];
	} else {
		targetElem.src = urlPrefix + "/" + foundArry[2];
	}
	
}

function clickHandler(e) {
	targetElement = getTargetElem(e);
	window.name = targetElement.id;
}

function loadMenu() {
	found = false;
	keyvalue = window.location.search.substr(1).split("&");
	cidPair = ("" + keyvalue).split("=");
	cpath = window.location.pathname;
	if(cidPair.length == 2 && cidPair[0] == "cid" && cidPair[1].length > 0) {
		cid = cidPair[1];
		found = true;
	}
	/*
	else {
		cid = menuData[0][0];
	}
	*/
	for(var i = 0; i < menuData.length; i++) {
		elemId = menuData[i][0];
		elem = document.getElementById(elemId);
		
		if(i == 0) {
			url = elem.src;
			urlPrefix = url.substr(0, url.lastIndexOf('/'));
		}
		
		if(elem.id == cid || (cpath.toLowerCase().indexOf(menuData[i][3].toLowerCase()) > 0) ) {
			elem.src = urlPrefix + "/" + menuData[i][1];
			found = true;
		}
		
		elem.onmouseover = mouseOverHandler;
		elem.onmouseout = mouseOutHandler;
		elem.parentNode.setAttribute('href', elem.parentNode.href + "?cid=" + menuData[i][0]);
	}
	
	if(!found) {
		cid = menuData[0][0];
		elem = document.getElementById(cid);
		elem.src = urlPrefix + "/" + menuData[0][1];
	}
	//if(window.name == null || window.name.length == 0) window.name=menuData[0][0]
}