var flashIsAvailable;
var plugin = (navigator.mimeTypes &&
  navigator.mimeTypes["application/x-shockwave-flash"] ?
  navigator.mimeTypes["application/x-shockwave-flash"].enabledPlugin : 0);
if (!((navigator.appName == "Microsoft Internet Explorer" &&
   navigator.appVersion.indexOf("Mac") == -1 &&
   navigator.appVersion.indexOf("3.1") == -1) ||
   (plugin && parseInt(plugin.description.substring(plugin.description.indexOf(".")-1))>=4)))
   flashIsAvailable = 0;
else
   flashIsAvailable = 1;