MooTools Full Screen Background - Asset.image

<style>#bg{position:fixed !important;position:absolute;bottom:0}</stylev<script>window.addEvent(load, function() {resize();});window.addEvent(resize,function(){resize();});

function resize(){win= window.getSize();if($(bg) !=null){$(bg).dispose();}var bg = new Element(div,{id:bg}).inject(document.body,top);bg.setStyles({overflow:hidden,top:0,left:0,width:win.x,height:win.y,display:block});
var image = bg1.jpg;var loader = new Asset.images(image, {onComplete: function() {var imgL = new Element(img,{src:image});imgL.setStyles({opacity:0});imgL.inject(bg);imgW = imgL.getSize().x;imgH = imgL.getSize().y;if(imgW/imgH>win.x/win.y){n_imgH = win.y; n_imgW = (win.y/imgH)*imgW;}else {n_imgH = (win.x/imgW)*imgH; n_imgW = win.x;}imgL.setStyles({width:n_imgW ,height:n_imgH,display:block,opacity:1});}});};
</script>