vedi se funziona
codice:
<html>
<head>
<script language="JavaScript">
<!--
function MM_checkPlugin(plgIn, theURL, altURL, autoGo) { //v4.0
var ok=false; document.MM_returnValue = false;
with (navigator) if (appName.indexOf('Microsoft')==-1 || (plugins && plugins.length)) {
ok=(plugins && plugins[plgIn]);
} else if (appVersion.indexOf('3.1')==-1) { //not Netscape or Win3.1
if (plgIn.indexOf("Flash")!=-1 && window.MM_flash!=null) ok=window.MM_flash;
else if (plgIn.indexOf("Director")!=-1 && window.MM_dir!=null) ok=window.MM_dir;
else ok=autoGo; }
if (!ok) theURL=altURL; if (theURL) window.location=theURL;
}
//-->
</script>
</head>
<body bgcolor="#FFFFFF" text="#FF9900" onLoad="MM_checkPlugin('Shockwave Flash','index_flash','index_noflash',true);return document.MM_returnValue">
<font face="Arial, Helvetica, sans-serif">Checking flash plugin.
Please wait... </font>
</body>
</html>