var images = [
            "resources/images/background/1.jpg",
            "resources/images/background/2.jpg",
            "resources/images/background/3.jpg",
            "resources/images/background/4.jpg",
            "resources/images/background/5.jpg",
            "resources/images/background/6.jpg",
            "resources/images/background/7.jpg",
            "resources/images/background/8.jpg",
            "resources/images/background/9.jpg",
            "resources/images/background/10.jpg",
            "resources/images/background/11.jpg",
            "resources/images/background/12.jpg",
            "resources/images/background/13.jpg" 
        ];
        
        var index = 0;
        
        $.backstretch(images[index], {speed: 2000});
        
        setInterval(function() {
            index = (index >= images.length - 1) ? 0 : index + 1;
            $.backstretch(images[index]);
        }, 8000);