Диаграммы в Excel

private void ConvertToExcel()
{
Excel.Application app = null;
Excel.Workbooks wbs = null;
Excel.Workbook wb = null;
Excel.Worksheet ws = null;

try
{
app = new Excel.ApplicationClass();
app.Visible = true;

wbs = (Excel.Workbooks)(app.GetType().InvokeMember("Workbooks",BindingFlags.GetProperty, null, app, null));
wb = (Excel.Workbook)(wbs.GetType().InvokeMember("Add",BindingFlags.InvokeMethod, null, wbs, null));

ws = (Excel.Worksheet)wb.ActiveSheet;
Excel.Range range = null;

for(int i=0; i<Count;i++)
  for(int j=0;j<this.dataSet2.Tables[0].Columns.Count;j++)
  {
     range = (Excel.Range)ws.Cells[i+1,j+1];
     if((i+1)==1)
     {
       range.Value2 = this.dataSet2.Tables[0].Columns[j].ColumnName.ToString();
       if((j+1)==1)
    range.Value2 = "№ пп";
       range.Interior.ColorIndex = 15;
      }
      else
      {
        if((j+1)==1)
      {
         range.Value2 = i.ToString();
      }
      else
         range.Value2 = this.dataSet2.Tables[0].Rows.ItemArray.GetValue(j).ToString();
      }
  }
System.Runtime.InteropServices.Marshal.ReleaseComObject(range);
}
finally
{
   if (ws != null)
       System.Runtime.InteropServices.Marshal.ReleaseComObject(ws);
   if (wb != null)
       System.Runtime.InteropServices.Marshal.ReleaseComObject(wb);
   if (app != null)
   {
     System.Runtime.InteropServices.Marshal.ReleaseComObject(app);
     GC.Collect();
     GC.WaitForPendingFinalizers();
     GC.Collect(); 
   }
}
}