在C#.net文件(.aspx)添加Javascript代码为何没有显示??(实现浮动广告)

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN" >
<HTML>
<HEAD>
<title>default</title>
<meta content="Microsoft Visual Studio .NET 7.1" name="GENERATOR">
<meta content="C#" name="CODE_LANGUAGE">
<meta content="JavaScript" name="vs_defaultClientScript">
<meta content="http://schemas.microsoft.com/intellisense/ie5" name="vs_targetSchema">
</HEAD>
<body MS_POSITIONING="GridLayout">
<form id="Form1" method="post" runat="server">
</form>
</body>
<script src="floatad.js"></script>
<div id="AdLayer" style='position:absolute; width:61px; height:59px; z-index:20; visibility:hidden;; left: 600px; top: 300px'>
<a href="http://www.5dmedia.com/bbs"><img src='images/online_cn3.gif' border="0" height="60" width="60">
</a>
</div>
</HTML>