public MainWindow() { InitializeComponent(); var ds = new DataSource(); if (ds != null) { LayoutPanel panel = new LayoutPanel() { Caption = "Live Report", AllowClose = false }; AccountDataSheet sheet = new AccountDataSheet() { DataContext = ds }; panel.Content = sheet; documents.Add(panel); panel.IsActive = true; } var bds = new BenchMarkDataSource(); if (bds != null) { LayoutPanel panel = new LayoutPanel() { Caption = "BenchMark Report", AllowClose = false }; BenchMarkDataSheet sheet = new BenchMarkDataSheet() { DataContext = bds }; panel.Content = sheet; documents.Add(panel); panel = new LayoutPanel() { Caption = "Report", AllowClose = false }; NewReportDataSheet Nsheet = new NewReportDataSheet() { DataContext = bds }; panel.Content = Nsheet; documents.Add(panel); panel.IsActive = true; } }