var imageGroup = 0;
var imageGroups = [[0, 5, 8], [1, 9, 4], [6, 3, 11], [7, 2, 10]];
var currentImage = [];

function fader() {
	setTimeout(function () {
		for (imageIndex = 0; imageIndex < imageGroups[imageGroup].length; imageIndex++) {
			image = imageGroups[imageGroup][imageIndex];
			lastImage = currentImage[image];
			if ( lastImage == (jQuery('#mainImage' + image + ' li').length - 1) )
				nextImage = 0;
			else
				nextImage = lastImage + 1;
			currentImage[image] = nextImage;
			jQuery('#mainImage' + image + ' li').eq(lastImage).fadeOut(750);			
			jQuery('#mainImage' + image + ' li').eq(nextImage).fadeIn(750);
		}
		imageGroup++;
		if ( imageGroup >= imageGroups.length ) {
			imageGroup = 0;
		}
		fader();
	}, 2000);	
}

jQuery(window).load(
	function() {
		for (imageIndex = 0; imageIndex < jQuery('#mainImage li').length; imageIndex++) {
			currentImage[imageIndex] = 0;
		}
		if ( typeof(pageImageGroups) != "undefined" ) {
			var imageGroups = pageImageGroups;
		}
		fader();
	}
);