function loadFileWithFILEfox() {
    // First, check if FILEfox is installed.
    if (!window.nsFILEfox) {
        alert("Sorry, you don't have the FILEfox extension installed.");
        return;
    }

    // OK, FILEfox version can be retrieved with the 'getVersion()' call.
    alert("BTW, you have FILEfox extension version " + nsFILEfox.getVersion());

    // Request a file through FILEfox:
    // (Keeping the returned data object in a private local variable so that other scripts on the page cannot read it.)
    var text_file = nsFILEfox.requestLoadASCIIFile(
                            'upload_policy_file_never',             // Specifying a valid file upload policy
                                                                    // to avoid an error message!
                            'upload_policy_derived_data_never',     // Specifying a valid the derived data upload policy
                                                                    // to avoid an error message!
                            "Corp XYZ JavaScript App",              // Company / JavaScript app name
                                                                    // Additional message to the user
                            "Please specify an XYZ data file for analysis.");
    if (!text_file) {
        alert("Could not get the file.  The user either canceled or there was an error");
        return;
    }

    alert("Got a text file with " + text_file.getTotalLines() + " total lines.");
    if (text_file.getTotalLines() > 0) {
        alert("The first line says:  '" + text_file.getLine(0) + "'");
    }
}