private boolean validateValue(String msg, int gridletId, int userId,
                int resourceId)
    {
        boolean valid = true;

        // Gridlet ID must be 0 or positive
        if (gridletId < 0)
        {
            valid = false;
            System.out.println(msg + "Error - Gridlet ID must be >= 0, not " +
                    gridletId);
        }

        // User ID must be 0 or positive
        if (userId < 0)
        {
            valid = false;
            System.out.println(msg + "Error - User ID must be >= 0, not " +
                    userId);
        }

        // GridResource ID must be 0 or positive
        if (resourceId < 0)
        {
            valid = false;
            System.out.println(msg +
                    "Error - GridResource ID must be >= 0, not " + resourceId);
        }

        // if a grid resource ID doesn't exist in GIS list
        if (!gis_.isResourceExist(resourceId))
        {
            valid = false;
            System.out.println(msg + "Error - GridResource ID #" + resourceId +
                               " doesn't exist");
        }

        return valid;
    }