Trigger:  I have to create a workaround which salesforce recommended me to use trigger. I need to create a visiblity to case. User A creates a ticket and the owner of ticket is assigned. The ticket is visible to owner and his/her group through case sharing rules. But the case is not visible to the actual person who created the ticket and the contact owner. The scenerio is I don't want anybody to view this ticket except Owner, the owner group and the creator. I tried using sharing setting but in that scenrio either all users are able to see or none of the users cannot see except owner and their group. Salesforce recommended me to use this sample trigger. Since I dont have much idea in trigger, this code is not working. Please help.

trigger CaseTeamTrigger on Case (after insert, after update) {

    Map<Id, CaseTeamMember> membersToAdd = new Map<Id, CaseTeamMember>();

    List<Case> cases = [Select Id,OwnerId,RecordTypeId,RecordType.Name

                  from Case where id IN :Trigger.newMap.keySet()];

      for (Case c : cases)

    {

        membersToAdd.put(c.Id, new CaseTeamMember(ParentId = c.Id, MemberId = UserInfo.getUserId()));      

    }   

    if (!membersToAdd.isEmpty()) {

      try {

        CaseTeamRole caseTeamRole = [SELECT Id FROM CaseTeamRole WHERE Name = 'Creator' LIMIT 1];

        for (CaseTeamMember ctm : membersToAdd.values()) {

          ctm.TeamRoleId = caseTeamRole.Id;

        }

        for (CaseTeamMember ctm : [SELECT Id, MemberId, ParentId

                       FROM CaseTeamMember

                       WHERE ParentId IN :membersToAdd.keySet()

                       AND MemberId = :UserInfo.getUserId()

                       ORDER BY ParentId])

 {

          if (membersToAdd.containsKey(ctm.ParentId)) {

            membersToAdd.remove(ctm.ParentId);

          }

        }

        if (!membersToAdd.isEmpty()) {

          insert membersToAdd.values();

        }

      } catch (System.QueryException qe) {}

    }

}

Please help.