// Browser Slide-Show script. With image cross fade effect for those browsers that support it.

var FadeDurationMS=1000;

function SetOpacity(object, opacityPct)
{
	
  // IE.
  object.style.filter = 'alpha(opacity=' + opacityPct + ')';
  // Old mozilla and firefox
  object.style.MozOpacity = opacityPct / 100;
  // Everything else.
  object.style.opacity = opacityPct / 100;
  
}

function ChangeOpacity(id, msDuration, msStart, fromO, toO)
{
	
  var element = document.getElementById(id);
  var msNow = (new Date()).getTime();
  var opacity = fromO + (toO - fromO) * (msNow - msStart) / msDuration;
  
  if (opacity >= 100)
  {
	  
    SetOpacity(element, 100);
    element.timer = undefined;
	
  }
  else if (opacity <= 0)
  {
	  
    SetOpacity(element,0);
    element.timer = undefined;
	
  }
  else 
  {
	  
    SetOpacity(element,opacity);
    element.timer = window.setTimeout("ChangeOpacity('" + id + "'," + msDuration + "," + msStart + "," + fromO + "," + toO + ")", 10);
	
  }
  
}

function FadeInImage(foregroundID,newImage,backgroundID)
{
	
  var foreground = document.getElementById(foregroundID);
  
  if (foreground.timer) 
  	window.clearTimeout(foreground.timer);
	
  if (backgroundID)
  {
	  
    var background = document.getElementById(backgroundID);
	
    if (background)
    {
		
      if (background.src)
      {
		  
        foreground.src = background.src; 
        SetOpacity(foreground, 100);
		
      }
	  
      background.src = newImage;
      background.style.backgroundImage = 'url(' + newImage + ')';
      background.style.backgroundRepeat = 'no-repeat';
	  
      var startMS = (new Date()).getTime();
	  
      foreground.timer = window.setTimeout("ChangeOpacity('" + foregroundID + "'," + FadeDurationMS + "," + startMS + ",100,0)", 10);
	  
    }
	
  } 
  else
    foreground.src = newImage;
	
}

var slideCache = new Array();

function RunSlideShow(pictureID, backgroundID, imageFiles, displaySecs)
{
	
  var imageSeparator = imageFiles.indexOf(";");
  var nextImage = imageFiles.substring(0, imageSeparator);
  
  FadeInImage(pictureID, nextImage, backgroundID);
  
  var futureImages = imageFiles.substring(imageSeparator + 1,imageFiles.length) + ';' + nextImage;
  
  setTimeout("RunSlideShow('" + pictureID + "','" + backgroundID + "','" + futureImages + "'," + displaySecs + ")",displaySecs * 1000);
  
  // Cache the next image to improve performance.
  imageSeparator = futureImages.indexOf(";");
  nextImage = futureImages.substring(0, imageSeparator);
  
  if (slideCache[nextImage] == null)
  {
	  
    slideCache[nextImage] = new Image;
    slideCache[nextImage].src = nextImage;
	
  }
  
}

function FadeInText(newText,backgroundID)
{
	
  if (backgroundID)
  {
	  
    var background = document.getElementById(backgroundID);
	
	  if (background.timer) 
		window.clearTimeout(background.timer);
	
    if (background)
    {
		
      SetOpacity(background, 0);
	  
	  var old = background.firstChild;
	  var txt = document.createTextNode(newText);
	  background.replaceChild(txt, old);
	  
      var startMS = (new Date()).getTime();
	  
      background.timer = window.setTimeout("ChangeOpacity('" + backgroundID + "'," + FadeDurationMS + "," + startMS + ",0,100)", 10);
	  
    }
	
  } 
  else
  {
   
   	  var old = background.firstChild;
	  var txt = document.createTextNode(newText);
	  background.replaceChild(txt, old);
	  
  }

}

function RunTextShow(backgroundID, textFiles, displaySecs)
{
	
  var textSeparator = textFiles.indexOf(";");
  var nextText = textFiles.substring(0, textSeparator);
  
  FadeInText(nextText, backgroundID);
  
  var futureTexts = textFiles.substring(textSeparator + 1,textFiles.length) + ';' + nextText;
  
  setTimeout("RunTextShow('" + backgroundID + "','" + futureTexts + "'," + displaySecs + ")",displaySecs * 1000);
  
  // Cache the next text to improve performance.
  textSeparator = futureTexts.indexOf(";");
  nextText = futureTexts.substring(0, textSeparator);
  
}