//Store current image number
var currentIndex = 0;
var nextIndex = 1;
var timeOutDelay = 6000;//Delay in milliseconds
var currentOpacity = new Array();
var FADE_STEP = 2;
var FADE_INTERVAL = 20;
var pause = false;
var browsertype;
var COUNTER;
var caseStudyIndex = 0;

//Store current image number
var currentIndex = 0;
var nextIndex = 1;
//Delay in milliseconds
var timeOutDelay = 6000;
var currentOpacity = new Array();
var FADE_STEP = 2;
var FADE_INTERVAL = 10;
var pause = false;
var browsertype;
var COUNTER;

//Initialise slideshow if the objects exist for it to work
function startSlideshow() {
	if (!document.getElementsByTagName || !document.getElementById || !document.getElementById(slideshowContainer)) {
		return false;
	}
	
	currentOpacity[0]=99;
	for(i=1; i<images.length; i++) {
		currentOpacity[i]=0;
	}

	var slideshow = document.getElementById(slideshowContainer);
	//remove existing image
	//slideshow.removeChild(slideshow.firstChild);
	var agt = navigator.userAgent.toLowerCase();
	var is_opera = (agt.indexOf("opera") != -1);
	//Browser check
	if(document.all && !is_opera) {
		browsertype = 'ie';
		//alert('ie');
	} else if (document.all && is_opera) {
		browsertype = 'opera';
		//alert('opera');
	} else {
		browsertype = 'moz';
		//alert('moz');
	}
	
	for(i=0; i<images.length; i++) {
		
		var newimage = document.createElement('IMG');
		newimage.setAttribute('id','image' + i);
		newimage.setAttribute('src',images[i]);
		newimage.setAttribute('alt',alttext[i]);
		newimage.className = "imgfade";
		
		slideshow.appendChild(newimage);
		
		if (browsertype == 'ie') {
			newimage.style.filter="alpha(opacity=0)";
		} else if (browsertype == 'moz') {
			newimage.style.MozOpacity = 0;
			newimage.style.opacity = 0;
		} else {
			newimage.style.visibility = 'hidden'
		}
	}

	//activate first image and hide original
	slideshow.removeChild(slideshow.firstChild);
	if (browsertype == 'ie') {
		document.getElementById('image'+currentIndex).style.filter="alpha(opacity=100)";
	} else if (browsertype == 'moz') {
		document.getElementById('image'+currentIndex).style.MozOpacity = .99;
		document.getElementById('image'+currentIndex).style.opacity = .99;
	} else {
		document.getElementById('image'+currentIndex).style.visibility = 'visible'
	}

	COUNTER = setTimeout("swapImage()",timeOutDelay);
}

function swapImage() {
	COUNTER = "";
	if (browsertype == 'ie') {
		doFade =  setInterval("crossFade()",FADE_INTERVAL);
	} else if (browsertype == 'moz') {
		doFade =  setInterval("crossFade()",FADE_INTERVAL);
	} else {
		document.getElementById('image'+currentIndex).style.visibility = 'hidden';
		document.getElementById('image'+nextIndex).style.visibility = 'visible';
		currentIndex = nextIndex;
		nextIndex++;
		if(nextIndex == images.length) { 
			nextIndex=0;
		}
	}
	COUNTER = setTimeout("swapImage()",timeOutDelay);
	//
	//
	caseStudyIndex ++;
	if(caseStudyIndex == case_study_urls.length){
	  caseStudyIndex = 0;
  }
  // Update casestudy text and link when swaping image
	document.getElementById('case_study_intro').innerHTML = case_study_intros[caseStudyIndex];
	document.getElementById('case_study_intro').href = case_study_urls[caseStudyIndex];
	document.getElementById('case_study_link').href = case_study_urls[caseStudyIndex];
}

function crossFade() {
	currentOpacity[currentIndex]-=FADE_STEP;
	currentOpacity[nextIndex] += FADE_STEP;

	if(document.all) {
		document.getElementById('image'+currentIndex).style.filter = "alpha(opacity=" + currentOpacity[currentIndex] + ")";
		document.getElementById('image'+nextIndex).style.filter = "alpha(opacity=" + currentOpacity[nextIndex] + ")";
	} else {
		document.getElementById('image'+currentIndex).style.MozOpacity = currentOpacity[currentIndex]/100;
		document.getElementById('image'+nextIndex).style.MozOpacity =currentOpacity[nextIndex]/100;
		//Safari
		document.getElementById('image'+currentIndex).style.opacity = currentOpacity[currentIndex]/100;
		document.getElementById('image'+nextIndex).style.opacity =currentOpacity[nextIndex]/100;
	}

	if(currentOpacity[nextIndex]/100>=.98) {
		currentIndex = nextIndex;
		nextIndex++;
		window.clearInterval(doFade);
		if(nextIndex == images.length) { 
			nextIndex=0;
		}
	}
}