var count = new Number();
var photoIDs = new Array();
var numOfPhotos =  new Number();

//Distribute Photo IDs to an Array for Easy Access and initialize controls and first Image
function createSlideShow(photoXML){
var imgHolder = document.getElementById("imgHolder");
numOfPhotos = photoXML.firstChild.childNodes.length;
for(i=0; i<numOfPhotos;i++){
photoIDs[i] = photoXML.firstChild.childNodes[i].getAttribute("id");
}
var randomNo=Math.floor(Math.random()*numOfPhotos);
changeImage(randomNo, imgHolder);
createSlideShowControls(imgHolder);
}


function changeImage(photoNo, targetElement){
document.getElementById("imgHolder").style.backgroundImage = "none";
if(photoNo>numOfPhotos-1){
photoNo=0;
}
if(photoNo<0){
photoNo=numOfPhotos-1;
}
count = photoNo;
getCorrectSize(photoIDs[count],targetElement);
}

function createSlideShowControls(targetElement){
var slideShowPrev = document.createElement("a");
slideShowPrev.setAttribute("id", "slideShowPrev");
slideShowPrev.setAttribute("title", "Previous Photo");
slideShowPrev.onclick = function(){
changeImage(count-1, targetElement);
}
var slideShowNext = document.createElement("a");
slideShowNext.setAttribute("id", "slideShowNext");
slideShowNext.setAttribute("title", "Next Photo");
slideShowNext.onclick = function(){
changeImage(count+1, targetElement);
}
targetElement.appendChild(slideShowNext);
targetElement.appendChild(slideShowPrev);
}

function initSlideShow(){
var xmlRequest = getHttpObject();

function getData(url){
xmlRequest.open("GET",url,true);
xmlRequest.onreadystatechange=requestStatus;
xmlRequest.setRequestHeader("Content-Type", "text/xml");
xmlRequest.send(null);
}
function requestStatus(){
if(xmlRequest.readyState == 4){
if(xmlRequest.status == 200){
var xmlResponse = xmlRequest.responseXML.documentElement;
removeWhiteSpace(xmlResponse);
createSlideShow(xmlResponse);
}
else{
//alert("Error Code:"+xmlRequest.status);
document.getElementById("imgHolder").style.backgroundImage = "url('http://www.churchwebsites.com/images/global/flickrAlt.jpg')";
}
}else{
//alert("Processing!");
}
}
if(xmlRequest != null){
var xmlReceived = getData(url);
}
}