无绑定子窗体，如何设置链接主字段和链接子字段

Private Sub Form_Open(Cancel As Integer)
  Dim cn As New ADODB.Connection
  Dim rs1 As New ADODB.Recordset
  Dim rs2 As New ADODB.Recordset
  Dim rs3 As New ADODB.Recordset
  'cn.CursorLocation = adUseClient
  cn.Open "Provider=Microsoft.Jet.OLEDB.4.0;Data Source=" & CurrentProject.Path & "\a.mdb;Persist Security Info=False"
  With rs1
  .ActiveConnection = cn
  .Source = "SELECT * FROM 表1"
  .LockType = adLockOptimistic
  .CursorLocation = adUseClient
  .CursorType = adOpenKeyset
  .Open
  End With
   
  With rs2
  .ActiveConnection = cn
  .Source = "SELECT * FROM 表2"
  .LockType = adLockOptimistic
  .CursorLocation = adUseClient
  .CursorType = adOpenKeyset
  .Open
  End With
   
  With rs3
  .ActiveConnection = cn
  .Source = "SELECT aa FROM 表3"
  .LockType = adLockOptimistic
  .CursorLocation = adUseClient
  .CursorType = adOpenKeyset
  .Open
  End With
   
  Set Me.Recordset = rs1
  Set Me!窗体子窗体.Form.Recordset = rs2

 '从这里开始出错 
  Forms!窗体.窗体子窗体.LinkMasterFields = "序号"
  Forms!窗体.窗体子窗体.LinkChildFields = "序号"

End Sub