I have 2 reports, "report1.rdlc" and "report2.rdlc" and I want to be able to swap betweent the 2 of them in a single report viewer ("rv_1"). I also have 3 buttons: btn_1 which does: rv_1.LocalReport.ReportEmbeddedResource = "Application1.Report1.rdlc" rv_1.RefreshReport() btn_2 which does: rv_1.LocalReport.ReportEmbeddedResource = "Application1.Report2.rdlc" rv_1.RefreshReport() btn_3 which does: dim rds as new ReportDataSource rds.name = rds.value = rv_1.reset() rv_1.LocalReport.DataSources.add(rds) rv_1.RefreshReport() Now no matter what I put for rds.name and rds.value it leaves me with "A data source instance has not been supplied for the data source 'dataSetName_TableName'. So my question is; what do I need to put there in order to get this to work correctly?