var hp_active = 'img';
var hp_current = 0;
var hp_path = '/static/img/';
var hp_images = [ 
     'home-slides-6.jpg', 'home-slides-7.jpg', 'home-slides-4.jpg', 'home-slides-1.jpg'  ];

function preload_hp() {
	for(var i=0;i<hp_images.length;i++) {
		var cached = document.createElement('img');
		cached.src = hp_path+hp_images[i];
	}
}

function switch_hp() {
	var el_img = dojo.byId('img-slideshow');
	var el_bg = dojo.byId('bg-slideshow');
	if (hp_current == (hp_images.length-1)) {
		hp_current = 0;
	} else {
		hp_current = hp_current + 1;
	}
	if (hp_active == 'img') {
		el_bg.setAttribute("style", "background-image: url('"+hp_path+hp_images[hp_current]+"');");
		dojo.fadeOut({ node: el_img, duration: 3500 }).play();
		hp_active = 'bg';
	} else {
		el_img.src = hp_path+hp_images[hp_current];
		dojo.fadeIn({ node: el_img, duration: 3500 }).play();
		hp_active = 'img';
	}
}