Bibding report to ReportViewe

protected void btnReport_Click(object sender, EventArgs e) {


   int Edition_ID = int.Parse(ddlEdition.SelectedItem.Value);
   int NPos_ID = int.Parse(ddlPosition.SelectedItem.Value);
   int Lang_ID = int.Parse(ddlLanguage.SelectedItem.Value);
   int NewsCategoryId = int.Parse(ddlType.SelectedItem.Value);
   int NewsPaper_ID = int.Parse(ddlNewsPaper.SelectedItem.Value);
   int TonalityID = int.Parse(ddlTonality.SelectedItem.Value);
   DateTime News_dt = DateTime.Parse(txtStartDate.Text);
   DateTime IssueDate = DateTime.Parse(txtEndDate.Text);




   if (ddlCoverReprt.SelectedValue == "Report by Coverage Count") {






          DataTable CoverageCount = new DataTable();
              List oNews = new List();
           NewsManager manNews = new NewsManager();


   oNews = manNews.FetchCoverageCount(Edition_ID, NewsCategoryId, NewsPaper_ID, Lang_ID, TonalityID, NPos_ID, News_dt, IssueDate);


 



   ReportViewer1.Visible = true;


   ReportDataSource rds = new ReportDataSource("CoverCountPage");
   ReportViewer1.Reset();
   ReportViewer1.ProcessingMode = ProcessingMode.Local;
   LocalReport rep = ReportViewer1.LocalReport;
   rep.Refresh();
   rep.ReportPath = "CoverageCountReport.rdlc";


   rds.Name = "ReportingDataset_CoverageCount";
   rds.Value = CoverageCount;
   rep.DataSources.Add(rds);
On click of a button i have to generate a report. 

this giving an error 
A data source instance has not been supplied for the data source 'CoverageCount'.


what could be possibly wrong....have no idea....