Is this what a working flash detect javascript looks like?
<!--
var plugin = (navigator.mimeTypes && navigator.mimeTypes["application/x-shockwave-flash"] ? navigator.mimeTypes["application/x-shockwave-flash"].enabledPlugin : 0);
if (plugin && parseInt(plugin.description.substring(plugin.description.indexOf(".")-1)) >= 4) {
document.write('<EMBED src="detect.swf" quality=high bgcolor=#ffffff ');
document.write(' swLiveConnect=FALSE WIDTH=80 HEIGHT=72');
document.write(' TYPE="application/x-shockwave-flash" PLUGINSPAGE="http://www.macromedia.com/shockwave/download/index.cgi?P1_Prod_Version=ShockwaveFlash">');
} else {
document.write('<IMG SRC="images/animation.gif" WIDTH=80 HEIGHT=72 BORDER=0>');
}<br/>
//-->