private void btnSystemTypeFilter_Click(object sender, EventArgs e)
        {
            ReportSystemTypeFilterDlg reportSTFilterDlg = new ReportSystemTypeFilterDlg(allValidSystemType, checkedSystemType);

            if (reportSTFilterDlg.ShowDialog() == DialogResult.OK)
            {
                List <string> checkedItems = new List <string>();
                for (int ii = 0; ii < SystemCheckList.Items.Count; ++ii)
                {
                    if (SystemCheckList.GetItemChecked(ii))
                    {
                        String itemName = SystemCheckList.Items[ii].ToString();
                        checkedItems.Add(itemName);
                    }
                }
                SystemCheckList.Items.Clear();
                allElementItems.Clear();

                foreach (Autodesk.Revit.DB.BuiltInCategory categoryId in filterCategories)
                {
                    ICollection <Autodesk.Revit.DB.Element> founds = PressureLossReportHelper.instance.getCategoryElements(categoryId);
                    addItemsToCheckList(PressureLossReportHelper.instance, founds, checkedItems);
                }
            }
        }
        private void btnSystemTypeFilter_Click(object sender, EventArgs e)
        {
            ReportSystemTypeFilterDlg reportSTFilterDlg = new ReportSystemTypeFilterDlg(allValidSystemType, checkedSystemType);
             if (reportSTFilterDlg.ShowDialog() == DialogResult.OK)
             {
            List<string> checkedItems = new List<string>();
            for (int ii = 0; ii < SystemCheckList.Items.Count; ++ii)
            {
               if (SystemCheckList.GetItemChecked(ii))
               {
                  String itemName = SystemCheckList.Items[ii].ToString();
                  checkedItems.Add(itemName);
               }
            }
            SystemCheckList.Items.Clear();
            allElementItems.Clear();

            foreach (Autodesk.Revit.DB.BuiltInCategory categoryId in filterCategories)
            {
               ICollection<Autodesk.Revit.DB.Element> founds = PressureLossReportHelper.instance.getCategoryElements(categoryId);
               addItemsToCheckList(PressureLossReportHelper.instance, founds, checkedItems);
            }
             }
        }