Dim MyForm2 As Form2
 
    Private Sub Button4_Click(ByVal sender As System.Object, ByVal e As _
      System.EventArgs) Handles Button4.Click
        MyForm2 = New Form2
        Me.AddOwnedForm(MyForm2)
        MyForm2.Visible = True
    End Sub
 
    Private Sub Form1_Deactivate(ByVal sender As Object, ByVal e As _
      System.EventArgs) Handles MyBase.Deactivate
        Me.Text = "Ich wurde deaktivert"
    End Sub
 
    Protected Overrides Sub OnDeactivate(ByVal e As System.EventArgs)
        If Array.IndexOf(Me.OwnedForms, MyForm2) > -1 Then
            Return
        End If
        MyBase.OnDeactivate(e)
    End Sub