Penso possa servire a qualcuno:
codice:
<!DOCTYPE HTML>
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=iso-8859-1">
<title>Banner</title>
<script language="javascript" type="text/javascript" src="https://ajax.googleapis.com/ajax/libs/jquery/1.7.2/jquery.min.js"></script>
<script type="text/javascript">
$(function(){
$(window).scroll(function() {
$('#ads').stop().animate({marginTop:$(window).scrollTop()});
});
});
</script>
<style type="text/css">
#sito{
width:920px;/*larghezza del sito*/
margin:auto;
height:2000px;
background:#ccc;
}
#ads{
/*dimensioni del banner*/
width:120px;
height:400px;
/*dimensioni del banner*/
margin-left:460px;/* Metà della larghezza totale del sito */
top:25px;/* Margine superiore del banner */
overflow:hidden;/* Serve per la chiusura */
position:absolute;
left:50%;
background:red;
text-align:right;
}
</style>
</head>
<body>
<div id="sito"></div>
<div id="ads">
X
</div>
</body>
</html>