// Fade effect only in IE; degrades gracefully

var ieFadeDur = 0.5;
var ieFadeTrans = 0;

// Internet Explorer?
var ie;
// will hold the preloaded slides
var slide = new Array();
var slideImg;
var slideDescriptionDiv;



function initSlideShow() {
  // first check whether the slideSrc array and the slideImg image are present
  if (typeof(slideCount) == "undefined" || 
    typeof(document.images.slideImg) == "undefined" ||
    slideCount < 2)
    return;
    
  ie = (navigator.appName == "Microsoft Internet Explorer");
    
  slideImg = document.images.slideImg;
  slideDescriptionDiv = document.getElementById('slideDescriptionDiv');
  
  // split file name
  var imgURL = slideImg.src;
  var ext = imgURL.substring(imgURL.lastIndexOf('.') + 1, imgURL.length);
  imgURL = imgURL.substring(0, imgURL.lastIndexOf('_') + 1);
  
  // preload slides
  for (var i = 0; i < slideCount; i++) { 
    slide[i] = new Image();
    slide[i].src = imgURL + (i + 1) + "." + ext;
    
    if (typeof(slideDescription) != "undefined" && i < slideDescription.length) {
      slide[i].alt = slideDescription[i];
      slide[i].title = slideDescription[i];
    }
  }
    
  if (ie)
    slideImg.style.filter = "blendTrans(Duration=" + ieFadeDur + ", Transition=" + ieFadeTrans + ")";
  
  // start with a random slide
  var startIndex = Math.round(Math.random() * (slideCount - 1));
  
  showSlide(startIndex);
}


function showSlide(slideNr){
  if (ie)
    slideImg.filters.blendTrans.Apply();
    
  if (typeof(slideDescriptionDiv) != "undefined" && typeof(slide[slideNr].alt) != "undefined")
    slideDescriptionDiv.innerHTML = slide[slideNr].alt;
    
  slideImg.src = slide[slideNr].src;
  slideImg.alt = slide[slideNr].alt;
  slideImg.title = slide[slideNr++].title;
   
  if (ie)
    slideImg.filters.blendTrans.Play();
   
  if (slideNr >= slide.length) 
    slideNr = 0;
     
  setTimeout('showSlide(' + slideNr + ')', slideDur);
}