public double TotalBoosterCount()
        {
            double wk1, wk2, wk3, totalBooster = 0;

            try
            {
                string val1 = TxtInputWk1.Text, val2 = TxtInputWk2.Text, val3 = TxtInputWk3.Text;
                if (double.TryParse(val1, out wk1) && double.TryParse(val2, out wk2) && double.TryParse(val3, out wk3))
                {
                    totalBooster = wk1 + wk2 + wk3;
                }
            }
            catch { TxtInputWk1.Clear(); }
            return(totalBooster);//25
        }
 private void CmbFarmerBatch_KeyDown(object sender, KeyEventArgs e)
 {
     if (e.KeyCode == Keys.Enter)
     {
         if (CmbFarmer.SelectedValue != null)
         {
             TxtInputWk1.Focus();
             e.Handled = true;
         }
         else
         {
             MessageBox.Show("Fill the 'Farmer batch' to continue...!", "Input Error", MessageBoxButtons.OK, MessageBoxIcon.Warning);
         }
     }
 }