Call WahrFalsch(B1, Z1S1, Z1S1Kna)

Function WahrFalsch(ByVal x As Boolean, ByVal y As _
  System.Windows.Forms.TabPage, ByVal z As System.Windows.Forms.Label)
        Dim nr As String
        Dim na As String
        Dim Lb1 As New System.Windows.Forms.Label
        If (x = True) Then
            TabControl1.TabPages.Add(y)
            na = String.Concat(y.Name, "Kna")
            Lb1.Name = na
            Lb1.Text = KnotnaText.Text
           z.Text = Lb1.Text 
            MsgBox(Lb1.Name)
            MsgBox(Lb1.Text)
            MsgBox(Z1S1Kna.Text)
        End If
    End Function