public string Execute(TaskInfo ti)
{
    // Create new instance of event log provider
    EventLogProvider eventLog = new EventLogProvider();
    string[] splitUsers = ti.TaskData.Split(';');

    foreach (string user in splitUsers)
    {
        // Get events matching the where condition
        string where = "UserName = '" + user + "'";
        DataSet events = eventLog.GetAllEvents(where, null);
        if (!DataHelper.DataSourceIsEmpty(events))
        {
            int cnt = 0;
            // Loop through the individual items
            foreach (DataRow eventDr in events.Tables[0].Rows)
            {
                // Create the object from DataRow
                EventLogInfo deleteEvent = new EventLogInfo(eventDr);
                //Delete log
                deleteEvent.Destroy();
                eventLog.SetEventLogInfo(deleteEvent);
                cnt++;
            }
            string detail = cnt.ToString() + " events of user '" + user + "' deleted from Event Log.";

            // Logs the execution of the task in the event log.
            EventLogProvider.LogInformation("DeleteUsers", "Execute", detail);
        }
    }
    return null;
}