C#

System.Threading.Timer timer;<br />
        private void StartThreadTimer()<br />
        {<br />
            timer = new System.Threading.Timer(TimerCallback, "hepp", 0, 5000);<br />
        }<br />
<br />
        void TimerCallback(object callbackObj)<br />
        {<br />
            if (Monitor.TryEnter(lockerObject))<br />
            {<br />
                try<br />
                {<br />
                    Thread.Sleep(1000); // If this task succeeds the timer should stop and no callbacks must be allowed to be called again<br />
                    timer.Dispose(); //Can this guarantee that no more callbacks will be called?<br />
                }<br />
                finally<br />
                {<br />
                    Monitor.Exit(lockerObject);<br />
                }<br />
            }<br />
        }

com.CommandText = "SELECT activities.*,company.CompanyName,contact.ContactName " +
                              "FROM company,activities,contact,company_type,activity_type " +
                              "WHERE (activityTypeID.CompanyID=company.CompanyID AND " +
                              "activities.ContactID=contact.ContactID AND " +
                              "activity_type.TypeID = activities.ActivityTypeID) " +
                              "AND " +
                              "(CompanyName=@CompanyName OR @CompanyName='') AND " +
                              "(contact.ContactID=@ContactID OR @ContactID=0) AND " +
                              "(activities.ActivityTypeID=@ActivityTypeID OR @ActivityTypeID=0) AND " +
                              "(company.CompanyTypeID=@CompanyTypeID OR @CompanyTypeID=0) AND " +
                              "(StartDate>=@StartDate AND StartDate<=@EndDate) AND " +
                              "(Reminder=@Reminder OR @Reminder=false)";
            
            com.Parameters.Add(new OleDbParameter("@CompanyName", companyName));
            com.Parameters.Add(new OleDbParameter("@ContactID", contactID));
            com.Parameters.Add(new OleDbParameter("@ActivityTypeID", activityTypeID));
            com.Parameters.Add(new OleDbParameter("@CompanyTypeID", companyTypeID));
            com.Parameters.Add("@StartDate", OleDbType.DBDate).Value = start;
            com.Parameters.Add("@EndDate", OleDbType.DBDate).Value = end;
            com.Parameters.Add(new OleDbParameter("@Reminder", reminder));

            DataTable dtAct = new DataTable();
            OleDbDataAdapter adapter = new OleDbDataAdapter(com);

            con.Open();
            adapter.Fill(dtAct);
            con.Close();