var gblPhotoShufflerDivId = "photo";
var gblPhotoShufflerImgId = "photoimg"; 
var gblImg;
var gblPauseSeconds = 4.25;
var gblFadeSeconds = .50;
var gblRotations = 100;

var gblDeckSize = gblImg.length;
var gblOpacity = 100;
var gblOnDeck = 0;
var gblStartImg;
var gblImageRotations = gblDeckSize * (gblRotations+1);

function photoShufflerLaunch()
{
	var theimg = document.getElementById(gblPhotoShufflerImgId);
      gblStartImg = theimg.src; // save away to show as final image

document.getElementById(gblPhotoShufflerDivId).style.backgroundImage='url(' + gblImg[gblOnDeck] + ')';
setTimeout("photoShufflerFade()",gblPauseSeconds*1000);
}

function photoShufflerFade()
{
	var theimg = document.getElementById(gblPhotoShufflerImgId);

	// determine delta based on number of fade seconds
// the slower the fade the more increments needed
      var fadeDelta = 100 / (30 * gblFadeSeconds);

// fade top out to reveal bottom image
if (gblOpacity < 2*fadeDelta ) 
{
  gblOpacity = 100;
  // stop the rotation if we're done
  if (gblImageRotations < 1) return;
  photoShufflerShuffle();
  // pause before next fade
        setTimeout("photoShufflerFade()",gblPauseSeconds*1000);
}
else
{
  gblOpacity -= fadeDelta;
  setOpacity(theimg,gblOpacity);
  setTimeout("photoShufflerFade()",30);  // 1/30th of a second
}
}

function photoShufflerShuffle()
{
var thediv = document.getElementById(gblPhotoShufflerDivId);
var theimg = document.getElementById(gblPhotoShufflerImgId);

// copy div background-image to img.src
theimg.src = gblImg[gblOnDeck];
// set img opacity to 100
setOpacity(theimg,100);

      // shuffle the deck
gblOnDeck = ++gblOnDeck % gblDeckSize;
// decrement rotation counter
if (--gblImageRotations < 1)
{
  // insert start/final image if we're done
  gblImg[gblOnDeck] = gblStartImg;
}

// slide next image underneath
thediv.style.backgroundImage='url(' + gblImg[gblOnDeck] + ')';
}

function setOpacity(obj, opacity) {
  opacity = (opacity == 100)?99.999:opacity;
  
  // IE/Win
  obj.style.filter = "alpha(opacity:"+opacity+")";
  
  // Safari<1.2, Konqueror
  obj.style.KHTMLOpacity = opacity/100;
 
  // Older Mozilla and Firefox
  obj.style.MozOpacity = opacity/100;
 
  // Safari 1.2, newer Firefox and Mozilla, CSS3
  obj.style.opacity = opacity/100;
}