private void StopBtn_Click(object sender, EventArgs e)
 {
     if (DefaultTmr.Enabled)
     {
         DefaultTmr.Stop();
     }
     else
     {
         DefaultTmr.Start();
     }
 }
        private void StartBtn_Click(object sender, EventArgs e)
        {
            DefaultChrt.ChartAreas[0].AxisX.Minimum = 0;
            curr_money = Double.Parse(StartMoneyTB.Text);
            startDate  = StartDateDTP.Value;
            double rent     = Double.Parse(RentTB.Text);
            double salaries = Double.Parse(SalaryTB.Text);

            tireFitting         = new Logic.TireFitting(startDate, rent, salaries);
            DefaultTmr.Interval = 500 - (int)SpeedNUD.Value * 10;
            DefaultTmr.Start();
        }