Improve PanelManager

EDMI_ClientSuite/Panels/BasePanel.vb

@@ -1,4 +1,8 @@
 Public Class BasePanel
-
     Public Property Caption As String
+    Public ReadOnly Property OwnerForm As Integer
+        Get
+            Return Parent?.Parent?.Tag
+        End Get
+    End Property
 End Class

EDMI_ClientSuite/Panels/DocumentPanel.vb

@@ -20,7 +20,9 @@ Public Class DocumentPanel
 
     Private Sub GridViewMain_RowClick(sender As Object, e As RowClickEventArgs) Handles GridViewMain.RowClick
         If e.Button = MouseButtons.Left And e.Clicks = 2 Then
-            MsgBox("Open Preview")
+            MsgBox($"Open Preview for form {OwnerForm}")
+
+            'TODO: Open Preview Panel for OwnerForm
         End If
     End Sub
 End Class