private void processSendButton() {
        //
        // make sure the the specified file exits
        //
        String fileName = fFileFullPathname.getText();
        File file = null;
        String[] recipients = null;
        WarningUI warning = null;

        if (fileName.length() == 0) {
            warning = new WarningUI(
                    fParentFrame,
                    StringDefs.ERROR,
                    StringDefs.FILE_NOT_SPECIFIED);
        } else {
            file = new File(fileName);
            recipients = StringUtil.parseToArray(fToList.getText());

            if (!file.exists()) {
                warning = new WarningUI(
                        fParentFrame,
                        StringDefs.ERROR,
                        StringDefs.FILE_NOT_FOUND);
            } else if (!file.canRead()) {
                warning = new WarningUI(
                        fParentFrame,
                        StringDefs.ERROR,
                        StringDefs.FILE_NOT_READABLE);
            } else if (!file.isFile()) {
                warning = new WarningUI(
                        fParentFrame,
                        StringDefs.ERROR,
                        StringDefs.FILE_NOT_FILE);
            } else if (recipients == null) {
                warning = new WarningUI(
                        fParentFrame,
                        StringDefs.ERROR,
                        StringDefs.RECIPIENT_NOT_SPECIFIED);
            }
        }

        if (warning != null) {
            warning.setVisible(true);
        } else {
            setVisible(false);
            FileSendThread fileSendThread
                    = new FileSendThread(file, recipients);
            fileSendThread.start();
        }
    }