var iSlideImgIndex = 0;
var iSlideElementPrefix = 'iSlide';

var lightboxVisibleElement = 'stimuli_lightbox';  //lightbox element


var iSlide = { 
  startup: function(options) 
  { 
	var pauseTime = 5;
	
	if (options && options.pause)
		pauseTime = options.pause;
	
	if ($(iSlideElementPrefix + 'Img') != null)
	{
		this.perexe = new PeriodicalExecuter( function(pe) { iSlide.cycle(pe); }, pauseTime); // change image every x seconds (5 default)
	}
  }, 
  cycle: function(pe) 
  { 
	if ($(lightboxVisibleElement) && $(lightboxVisibleElement).visible()) // do nothing if the user has clicked on an image and shows it in lightbox.
		return;
		
	try 
	{
		$(iSlideElementPrefix + 'Img')
			.setStyle({
				width: iSlideAlbumArray[iSlideImgIndex].width + 'px', 
				height: iSlideAlbumArray[iSlideImgIndex].height + 'px'})
			.src = iSlideAlbumArray[iSlideImgIndex].small_img;

		$(iSlideElementPrefix + 'Href').href = iSlideAlbumArray[iSlideImgIndex].large_img;
		
		iSlideImgIndex++;
		
		if (iSlideImgIndex > iSlideAlbumArray.length-1)
			iSlideImgIndex = 0;
	} 
	catch (err) { pe.stop(); }
  },
  pause: function() 
  {
	this.perexe.pause();
  }
}