var overrider = {

    load : function() {
            Components.classes["@mozilla.org/docloaderservice;1"].getService(Components.interfaces.nsIWebProgress).
                addProgressListener(overrider.listener, Components.interfaces.nsIWebProgress.NOTIFY_LOCATION);
    },

    listener : {

        QueryInterface : function(id)
        {
            if(id.equals(Components.interfaces.nsIWebProgressListener) ||
                    id.equals(Components.interfaces.nsISupportsWeakReference) ||
                    id.equals(Components.interfaces.nsISupports))
                return this;

            throw Components.results.NS_NOINTERFACE;
        },

        /* ловим загрузку страницы */

        onLocationChange : function(progress, request, uri)
        {
            if(["http", "https", "file"].indexOf(uri.scheme) == -1)
                return false;

            var win = progress.DOMWindow.window.wrappedJSObject, sandbox = new Components.utils.Sandbox(win),
                args = [overrider.get_num("screen_width"), overrider.get_str("flash_version")];
            sandbox.window = win;
            Components.utils.evalInSandbox("(" + overrider.override.toSource() + ")('" + args.join("', '") + "')", sandbox);

            return true;
        }

    },

    /* основной хак */

    override : function(screen_width, flash_version)
    {
        window.screen.__defineGetter__("width", function() {
            return screen_width;
        });

        // ...

        window.navigator.plugins["Shockwave Flash"].__defineGetter__("version", function() {
            return flash_version;
        });

        // ...
    }

}