var pre		= base_url + 'images/assets/featurettes/';

function start_swap( array, id ){ 
	var index	= 0;
	for( var i = 0; i < array.length; i++ ){
		var image = new Image();
		image.src = array[i];
	}
	setInterval(function(){
		swap_bg( array[index], id );
		index++;
		index = ( index >= array.length ) ? 0: index;
						 }, 6000 );
}
function swap_bg( img_src, id ){
	var div = document.getElementById(id); 
	new Effect.Fade(id);
	setTimeout( function(){
		div.style.backgroundImage = "url('"+img_src+"')";
		new Effect.Appear(id);
						 }, 1200 );
}