A data source instance has not been supplied for the data - rdlc

A data source instance has not been supplied for the data source 'DS_EMPDEPT_Profile'. i get the above error when i am tryin t o view rdlc report i have this code ReportViewer1.LocalReport.ReportPath = Server.MapPath("reports/DEP.rdlc");             ReportDataSource rdS = new ReportDataSource("DS_EMPDEPT_Profile", GetData());             ReportViewer1.LocalReport.DataSources.Clear();