var supported = (document.getElementById || document.all);
if (supported)
{
   document.write("<style type='text/css'>");
   document.write("div.slide { display:none; }");
   document.write("</style>");
}

// Array of all slides
var allSlides;
// Slide counter
var currSlide = 0;

// Set global with array of slide elements
function getAllSlides() {
   var allChildren = document.getElementById("slides").childNodes;
   var slideElems = new Array();
   for (var i = 0; i < allChildren.length; i++) {
      if (allChildren[i].nodeType == 1) {
         slideElems[slideElems.length] = allChildren[i];
      }
   }
   allSlides = slideElems;
   allSlides[currSlide].style.display = "block";
}

// Advance to next slide
function next() {
   if (currSlide < 0) {
      allSlides[++currSlide].style.display = "block";
   } else if (currSlide < allSlides.length - 1) {
      allSlides[currSlide].style.display = "none";
      allSlides[++currSlide].style.display = "block";
   } else if (currSlide == allSlides.length - 1) {
      allSlides[currSlide++].style.display = "none";
      currSlide = -1;
      next();
   }
}

// Go to previous slide
function prev() {
   if (currSlide > allSlides.length - 1) {
      allSlides[--currSlide].style.display = "block";
   } else if (currSlide > 0) {
      allSlides[currSlide].style.display = "none";
      allSlides[--currSlide].style.display = "block";
   } else if (currSlide == 0) {
      allSlides[currSlide--].style.display = "none";
      currSlide = allSlides.length;
      prev();
   }
}

// Initialize slide show
function initSlides() {
   getAllSlides();
}