login error while loading crystal report using MICROSOFT ACCESS DB

when report is loaded then it asks for the user name and password it's very shocking for me cos i haven't used any user name or password while at the time of creating Database in MS ACCESS. and i don't know which password and username is required for the report weither it's database username and passwrod or any thing else ..... i have used following code to
DetailRpt rpt = new DetailRpt();
rpt.Refresh();
crystalReportViewer1.ReportSource = rpt;
crystalReportViewer1.SelectionFormula = "{Archival_Scanning.Assign_To}='" + txtName.Text + "'";