请问如下代码,怎么改,能在firefox下用

<html>
<head>
<script language="JavaScript" src="js/flash_new.js"></script>
<script language="JavaScript" src="js/util.js"></script>
<script language="JavaScript" event="fscommand()" for="eclose">
document.getElementById("FlashTest").style.visibility='hidden'; 
var today=new Date()
var begin=today.getSeconds() 
AutoShow(begin);
</script> 
</head>
<body>
<div id=FlashTest style='position: absolute;visibility:visible;z-index:1000'>
<script language=JavaScript>
webload();
big_flash_url="swf/bbb.swf";
AC_FL_RunContent('id','eclose','src',big_flash_url, 'movie',big_flash_url,'width','170','height','130','codebase','http://download.macromedia.com/pub/shockwave/cabs/flash/swflash.cab#version=6,0,29,0','quality','high','pluginspage','http://www.macromedia.com/go/getflashplayer' ); 
</script>
</div>
</body>
</html>就是一个浮动flash广告的关闭