Database Logon failed

I am new to crystal report. I want to bind crystal report viewer to the datatable fetched from the database through store procedure by passing the parameter through text box. Bt m getting the error database logon failed , code behid coding is: 

oSubmitReportBLL.PostedOn = txtDate1.Text.Trim();
        DataTable  dt= new DataTable();
        dt = oSubmitReportBLL.SelectRecievedReports();

      
        ReportDocument r = new ReportDocument();
        string reportpath = Server.MapPath("~/CrystalReport.rpt");
        r.Load(reportpath);
        DataSet DataSet1 = new DataSet();
        DataSet1.Tables.Add(dt);
        r.SetDataSource(DataSet1);
        CrystalReportViewer1.ReportSource = r;