if (navigator.plugins) 
{
  for (i=0; i < navigator.plugins.length; i++ ) 
  {
    if (navigator.plugins[i].name.indexOf("QuickTime") >= 0)
    { 
      haveqt = true;
    }
  }
}

 
if ((navigator.appVersion.indexOf("Mac") > 0) && (navigator.appName.substring(0,9) == "Microsoft")&& (parseInt(navigator.appVersion) < 5) )
{ 
  haveqt = true; 
}