function doxhr(url){
	if(!document.getElementById || !document.createTextNode){return;}		
	var request;
	try{
		request = new XMLHttpRequest();
	}catch(error){
		try{
			request = new ActiveXObject("Microsoft.XMLHTTP");
		}catch(error){
			document.getElementById("activityContent").innerHTML = "Please upgrade your browser";
			return;
		}
	}
		
	request.open('get',url,true);
	request.onreadystatechange=function(){			
		if(request.readyState == 4){
			if (request.status && /200|304/.test(request.status))
			{
				retrieved(request);
			} else{
				failed(request);
			}
		}
	}
	request.setRequestHeader('If-Modified-Since','Wed, 05 Apr 2006 00:00:00 GMT');
	request.send(null);		
}

function retrieved(requester) {		
	var data=requester.responseXML;
	var activity = data.getElementsByTagName("snippet");
	activitiesCount = activity.length - 1;
	for(var i = 0; i < activity.length; i++) {
		activities[i] = activity[i].firstChild.nodeValue;
		titles[i] = activity[i].getAttribute("title");
		authors[i] = activity[i].getAttribute("author");
    }
	obj = document.getElementById("activityContent");
	var text = '<h3>' + titles[0] + '</h3>';
	if (authors[0] != "" && authors[0] != null)
	{
		text += '<p class="submitted_by">Submitted by ' + authors[0] + '</p>';
	}
	text += '<p>' + activities[0] + '</p>'
	obj.innerHTML = text;
		
}
function failed(requester){
	//alert('The XMLHttpRequest failed. Status: '+requester.status);  	
}

var activities = new Array();
var titles = new Array();
var authors = new Array();
var activitiesCount;

// Set initial variables

activitiesLink = 0;

function getNextHeadline() {
	++activitiesLink;
	if (activitiesLink > activitiesCount) activitiesLink = 0;
	obj = document.getElementById("activityContent");
	var text = '<h3>' + titles[activitiesLink] + '</h3>';
	if (authors[activitiesLink] != "" && authors[activitiesLink] != null) {
		text += '<p class="submitted_by">Submitted by ' + authors[activitiesLink] + '</p>';
	}
	text += '<p>' + activities[activitiesLink] + '</p>';
	obj.innerHTML = text;
}

function getPrevHeadline() {
	--activitiesLink;
	if (activitiesLink < 0) activitiesLink = activitiesCount;
	obj = document.getElementById("activityContent");
	var text = '<h3>' + titles[activitiesLink] + '</h3>';
	if (authors[activitiesLink] != "" && authors[activitiesLink] != null) {
		text += '<p class="submitted_by">Submitted by ' + authors[activitiesLink] + '</p>';
	}
	text += '<p>' + activities[activitiesLink] + '</p>';
	obj.innerHTML = text;
}

function init() {
	doxhr("/content/xml_snippets/activities.xml");
}

window.onload = init;