Как вариант:

Код:
<HTML>
<HEAD></HEAD>
<SCRIPT LANGUAGE=JavaScript1.1>
<!--
var MM_contentVersion = 6;
var plugin = (navigator.mimeTypes && navigator.mimeTypes["application/x-shockwave-flash"]) ? navigator.mimeTypes["application/x-shockwave-flash"].enabledPlugin : 0;
if ( plugin ) {
var words = navigator.plugins["Shockwave Flash"].description.split(" ");
for (var i = 0; i < words.length; ++i)
{
if (isNaN(parseInt(words[i])))
continue;
var MM_PluginVersion = words[i];
}
var MM_FlashCanPlay = MM_PluginVersion >= MM_contentVersion;
}
else if (navigator.userAgent && navigator.userAgent.indexOf("MSIE")>=0
&& (navigator.appVersion.indexOf("Win") != -1)) {
document.write('<SCR' + 'IPT LANGUAGE=VBScript\\> \\n'); //FS hide this from IE4.5 Mac by splitting the tag
document.write('on error resume next \\n');
document.write('MM_FlashCanPlay = ( IsObject(CreateObject("ShockwaveFlash.ShockwaveFlash." & MM_contentVersion)))\\n');
document.write('</SCR' + 'IPT\\> \\n');
}
if ( MM_FlashCanPlay ) {
window.location="Flash.html";
} else{
window.location="HTML.html";
}
//-->
</SCRIPT>
<NOSCRIPT>
<CENTER>This site use JavaScript.<BR>Please, turn on JavaScript in your browser.</CENTER>
</NOSCRIPT>
</BODY>
</HTML>