private static String inputConnectionString(String defaultString) {
        InputDialog inputDialog = new InputDialog(shell);
        inputDialog.setTitle(bundle.getString("start.connection.title"));
        inputDialog.setText(bundle.getString("start.connection.message"));
        
        
        String connectionString = null;
        String inputValue = inputDialog.open(defaultString);
        if (inputValue == null) {
            return null;
        }
        connectionString = inputValue;
        if (connectionString==null||connectionString.equals("")) {
            connectionString = DEFAULT_CONNECTION_STRING;
        }
        return inputValue == null ? null : (String) inputValue;
    }