private void loadReport()
{
List <CustomerPurchase> cp = rc.CustomerPurchaseLists(dtfrom.Value, dtto.Value);
reportViewer1.ProcessingMode = ProcessingMode.Local;
ReportDataSource dtsource = new ReportDataSource("DataSet1", cp);
reportViewer1.LocalReport.ReportPath = "rpts/customerPurchase.rdlc";
reportViewer1.LocalReport.DataSources.Add(dtsource);
reportViewer1.Visible = true;
reportViewer1.RefreshReport();
}