Código HTML:
<html>
<head>
<style type="text/css">
body {margin:0; background:#000}
#body {background:#222;width:100%; height:100%; filter:Alpha(Opacity=100,
FinishOpacity=0, Style=1, StartX=0, StartY=0, FinishX=0, FinishY=100%)}
</style>
</head>
<body>
<div id="body"></div>
</body>
</html>