foreach (LogJobHistoryClass jhc in s.Log.GetJobHistory("JobId", DateTime.Now.AddDays(7), DateTime.Now))
                {
                    if (jhc.ExitCode!=0)
                    {
                        // do something
                    }
                }

                foreach (LogJobHistoryClass jhc in s.Log.GetJobHistory("JobId", DateTime.Now.AddDays(7), DateTime.Now))
                {
                    foreach (LogTaskHistoryClass thc in s.Log.GetTaskExecutionHistory(jhc.ExecutionId))
                    {

                    }
                }