Public Sub Form2Closed(ByVal sender As Object, ByVal e As System.EventArgs)
        If sender Is myForm2 Then
            RemoveHandler Form2Closed.Closed, AddressOf Form2Closed
            myForm2 = Nothing
        End If
 
    End Sub
 
Private Sub Umbenennen_Click(ByVal sender As System.Object, ByVal e As _
  System.EventArgs) _
            Handles Umbenennen.Click    
    myForm2 = New FormUmbenennen()
    myForm2.Show()
    AddHandler myForm2.Closed, AddressOf Form2Closed
End Sub