private void btnAccept_Click(object sender, EventArgs e)
 {
     try
     {
         PivotGridField newBonus = GetNewInvisibleBonusField();
         newBonus.Visible = true;
         //newBonus.AreaIndex = PivotGrid.Fields["BonusAmount"].AreaIndex;
         PivotGrid.Fields.Add(newBonus);
         txtFieldName.Text          = string.Empty;
         btnAccept.Enabled          = false;
         txtFieldExpression.Text    = string.Empty;
         txtFieldExpression.Enabled = false;
         PivotGrid.BestFit();
         DialogResult = DialogResult.OK;
     }
     catch (Exception ex)
     {
         if (CDS.Shared.Exception.UserInterfaceExceptionHandler.HandleException(ref ex))
         {
             throw ex;
         }
     }
 }