/**
 * Image/text periodic loader
 * */

var xmlHttp = null;
var nshow_xml = new Array;
var ns_url = "/slide/content/nshow.xml?"+Math.random();
var current_item = 0;

var ns_items = new Array;
var ns_paused = 0;

function GetXmlHttpObject()
{
	var xmlHttp=null;
	try
	  {
	  // Firefox, Opera 8.0+, Safari
	  xmlHttp=new XMLHttpRequest();
	  }
	catch (e)
	  {
	  // Internet Explorer
	  try
		{
		xmlHttp=new ActiveXObject("Msxml2.XMLHTTP");
		}
	  catch (e)
		{
		xmlHttp=new ActiveXObject("Microsoft.XMLHTTP");
		}
	  }
	return xmlHttp;
}

function ns_start() {
	xmlHttp = GetXmlHttpObject();
	xmlHttp.onreadystatechange = beginSubst;
	
	xmlHttp.open("GET",ns_url,true);
	xmlHttp.send(null);
}

function beginSubst() {
	
	if (xmlHttp.readyState==4)
	{
		
		nshow_xml = xmlHttp.responseXML.documentElement;	
		
		//fill array
		var _items = nshow_xml.getElementsByTagName("ns_item");
		
		for( i = 0 ; i < _items.length; i++) {
			ns_items[i] = new Array;
			ns_items[i]['img'] = _items[i].getElementsByTagName("picture")[0].getAttribute("src");
			ns_items[i]['text'] = _items[i].getElementsByTagName("text")[0].childNodes[0].nodeValue;
			ns_items[i]['header'] = _items[i].getElementsByTagName("header")[0].childNodes[0].nodeValue;
			ns_items[i]['link'] = _items[i].getElementsByTagName("link")[0].getAttribute("href");
		};
		
		//preload images
		
		preload_image_object = new Image();
		
		for( i = 0 ; i < _items.length; i++) {
			preload_image_object.src = ns_items[i]['img'];
		}
		
		current_item = 0;
		ns_sequense();
	}
}


function ns_sequense() {
	displayNsItem(current_item);		
	setTimeout('play()',5000);
}



function play() {
	if(! ns_paused ) {
		ns_next();
	}
	setTimeout('play()',5000);	
}

function ns_back() {
	if( current_item == 0 ) { 
		current_item = ns_items.length - 1;
	} else {
		current_item--;
	}
	displayNsItem(current_item);
}

function ns_next() {	
	if( current_item < ns_items.length - 1 ) { 
		current_item++
	} else {
		current_item = 0;
	}
	displayNsItem(current_item);
}

function ns_pause() {
	ns_paused = 1;
	switchPausedFlag(ns_paused);
}

function switchPausedFlag() {
	var img = (ns_paused) ?  "/slide/play.png" : "/slide/pause.png";
	var img_obj = document.getElementById("ns_play_pause");
	img_obj.src = img;
	
}

function displayNsItem() {
	var imgHolder = document.getElementById("ns_image");
	imgHolder.src = ns_items[current_item]['img'];
	var headerHolder = document.getElementById('ss_news_header');
	headerHolder.innerHTML = ns_items[current_item]['header'];
	var textHolder = document.getElementById('ss_news_teaser');
	textHolder.innerHTML = ns_items[current_item]['text'];
	document.getElementById('ns_link_reference').href = ns_items[current_item]['link'];
}

function prevBtn() {
	ns_pause();
	ns_back();
}

function nextBtn() {
	ns_pause();
	ns_next();
}

function playPauseBtn() {
	ns_paused = !ns_paused;
	switchPausedFlag(ns_paused);
}