Private Sub ScrollListBox(box As ListBox, tBar As TrackBar)
If box Is Nothing OrElse tBar Is Nothing OrElse box.Items.Count < (box.Height \ box.ItemHeight) Then
Return
End If
box.SuspendLayout()
Dim pct = tBar.Value / (tBar.Maximum - tBar.Minimum)
Dim pageItems = box.Height \ box.ItemHeight
Dim lbIndex = Math.Max(0, CInt((pct * box.Items.Count) - (pageItems / 2)))
box.TopIndex = lbIndex
box.ResumeLayout()
End Sub