Strange Javascript Error

Hey everyone… I have this javaScript function to call my flash app…

function initialize() {
  if (navigator.appName.indexOf("Microsoft") != -1) {
    flash = window.menubar;
  else {
    flash = window.document.menubar;

The line in bold is causing an error on my bosses computer. Now, it is only on his computer, when he runs IE 6 that he is getting this error. No one else has ever seen or reported it. runCollapseMenu will cause the menubar to contract…

Of course, he believes this is my fault, but I can’t for the life of me reproduce the error (no matter what version of IE I use). This is giving me a big headache… does anyone know why a javascript function simply doing a callback to flash would give this error? I use these in a lot of places and have never seen it, and it appears that it’s only on this page that it’s happening…

Thank you,