public IHttpActionResult DeleteOrganisationStaffMember(Guid id, Guid? projId, Guid staffId) {
      try {
        var staff = repo_.DeleteStaffMember(id, staffId);
        if (projId.HasValue)
          staff = staff.Where(sm => sm.ProjectIds.Contains(projId.Value)).ToList();

        return Ok(staff);
      } catch (Exception e) {
        return BadRequest(e.Message);
      }
    } // DeleteOrganisationStaffMember