CRM Online Retreive Plugin

//Extract the tracing service for use in debugging sandboxed plug-ins.
            ITracingService tracingService =
                (ITracingService)serviceProvider.GetService(typeof(ITracingService));
            
            // Obtain the execution context from the service provider.
            Microsoft.Xrm.Sdk.IPluginExecutionContext context = (Microsoft.Xrm.Sdk.IPluginExecutionContext)
                    serviceProvider.GetService(typeof(Microsoft.Xrm.Sdk.IPluginExecutionContext));

            IOrganizationServiceFactory serviceFactory = (IOrganizationServiceFactory)serviceProvider.GetService(typeof(IOrganizationServiceFactory));
            IOrganizationService service = serviceFactory.CreateOrganizationService(context.UserId);
            
            // The InputParameters collection contains all the data passed in the message request.            
            if (context.InputParameters.Contains("Target") && context.InputParameters["Target"] is Entity)
            {
                //Entity entityWBSDetail = (Entity)context.InputParameters["Target"];
                
                // Obtain the target entity from the input parmameters.
                //EntityReference entityRef = (EntityReference)context.InputParameters["Target"];                
                Guid ParentGuid = Guid.Empty;
                Entity ParentEntity = new Entity("new_wbsdetail");
                Entity CurrEntity = new Entity("new_wbsdetail");

                try
                {
                    tracingService.Trace("create entity Entity");
                    Entity entity = (Entity)context.InputParameters["Target"];
                    //Instead of getting entity from Target, we use the Image

                    //ParentGuid = entity.GetAttributeValue<Guid>("new_parentwbsdetailid");                    
                    tracingService.Trace("Before Entity");
                    CurrEntity = service.Retrieve("new_wbsdetail", entity.Id, new ColumnSet(new string[] { "new_name", "new_parentwbsdetailid" }));
                    tracingService.Trace("After Entity");
                    EntityReference EntityRef = ((EntityReference)(CurrEntity.Attributes["new_parentwbsdetailid"]));
                    tracingService.Trace("My Lookup ID {0}" + EntityRef.Id);
                    ParentEntity = service.Retrieve("new_wbsdetail", EntityRef.Id, new ColumnSet(new string[] { "new_name", "new_parentwbsdetailid" }));
                    tracingService.Trace("Parent Entity {0}", CurrEntity["new_name"]);

                    ParentEntity.Attributes["new_name"] = "test1";
                    //tracingService.Trace("Parent Entity Est No of Hours {0}", ParentEntity["new_estnoofhours"]);
                    
                    tracingService.Trace("Test");
                    service.Update(ParentEntity);
                    tracingService.Trace("AFter Update");                    
                }
                catch (Exception ex)
                {
                    tracingService.Trace("Updating Parent Record: {0}", ex.ToString());
                    throw;
                }                
            }