private void bw_DoWork(object sender, DoWorkEventArgs e)
 {
     var storeId = Convert.ToInt32(e.Argument);
     var bal = new Balance();
     dtIssueDate.Value = DateTime.Now;
     dtIssueDate.CustomFormat = "MM/dd/yyyy";
     DateTime dtCurrent = ConvertDate.DateConverter(dtIssueDate.Text);
     switch (VisibilitySetting.HandleUnits)
     {
         case 1:
             {
               e.Result = bal.ItemListToIssue(storeId, dtCurrent, _selectedType, bw);
             }
             break;
         case 2:
             {
                 e.Result = bal.ItemsListToIssueByUnit(storeId, dtCurrent, _selectedType, bw);
             }
             break;
         default:
             {
                 e.Result = bal.ItemsListToIssueByUnit(storeId, dtCurrent, _selectedType, bw);
             }
             break;
     }
 }