I have a series of images that cycle through a slideshow as css `background` properties. The code below should also have them fade in and out via jQuery's `fadeIn` property, but for some reason it does not fade, and simply changes instead. Any ideas? 

This is a follow up from a comment that was never solved. Fiddle here: <http://jsfiddle.net/5fVZ7/6/>

```
var images=new Array();
images[0]='http://s29.postimg.org/912bsm0mf/dataarancio.jpg';
images[1]='http://s27.postimg.org/y6tl17eb7/velocita.jpg';
var nextimage=0;
doSlideshow();

function doSlideshow(){
    if(nextimage>=images.length){nextimage=0;}
    $('.bkg')
    .css('background-image','url("'+images[nextimage++]+'")')
    .fadeIn(500,function(){
    setTimeout(doSlideshow,4000);
});
}

```