var updateContentObj = null;
var updateRightObj = null;
var updateMenuObj = null;

function getHTTPObject() {
	if (window.ActiveXObject) {
		return new ActiveXObject("Microsoft.XMLHTTP");
	} else if (window.XMLHttpRequest) {
		return new XMLHttpRequest();
	} else {
		alert("Your browser does not support AJAX.");
		return null;
	}
}

function nav(url, nav) {
	updateContentObj = updateDiv(url, nav, 'content', updateContentCallback, '&nav=' + nav);
	updateRightObj = updateDiv(url, nav, 'right', updateRightCallback, '&nav=' + nav + "&updateright=true");
	updateMenuObj = updateDiv(url, nav, 'menu', updateMenuCallback, '&nav=' + nav + "&updatemenu=true");
}

function updateDiv(url, nav, div, callback, vars) {
	obj = getHTTPObject();
	document.getElementById(div).innerHTML ="<center><img src='images/loading.gif'></center>";
	obj.onreadystatechange = callback;
	obj.open("GET", url + vars);
	obj.send(null);
	return obj;
}

function updateContentCallback() {
	if (updateContentObj.readyState == 4 && updateContentObj.status == 200) {
		document.getElementById('content').innerHTML = updateContentObj.responseText;
	}
}

function updateRightCallback() {
	if (updateRightObj.readyState == 4 && updateRightObj.status == 200) {
		document.getElementById('right').innerHTML = updateRightObj.responseText;
	}
}

function updateMenuCallback() {
	if (updateMenuObj.readyState == 4 && updateMenuObj.status == 200) {
		document.getElementById('menu').innerHTML = updateMenuObj.responseText;
	}
}