Private Sub Form1_Resize(sender As Object, e As System.EventArgs) Handles _
      Me.Resize
 
        Dim platz As Integer = Me.Width - Button1.Width - 20
 
        ListBox2.Left = platz / 2
 
        ListBox1.Width = ListBox2.Left - 20 - ListBox1.Left
        ListBox2.Width = ListBox1.Width
 
    End Sub

EALA FREYA FRESENA