<head>
<style>
#WallPaper0 {
position :absolute;
background :url('http://javascript.ru/forum/images/ca_serenity/misc/logo.gif');
height :128px;
width :128px;
}
#WallPaper1 {
position :absolute;
background :url('http://a.disquscdn.com/1489123367/images/noavatar92.png');
height :128px;
width :128px;
}
</style>
<script>
var wallpaper = 0,
wallslide = 0;
function fader() {
setTimeout(fader, 25);
document.getElementById("WallPaper" + wallpaper).style.opacity = 1.0 - Math.abs(100 - wallslide) / 100;
wallslide -= 5;
if(wallslide < 0) {
wallslide = (wallslide + 200) % 200;
wallpaper ++;
if(!document.getElementById("WallPaper" + wallpaper))
wallpaper = 0;
}
}
</script>
</head>
<body onload='fader()'>
<span id=WallPaper0>para</span>
<span id=WallPaper1>head</span>
</body>