Question: How to shorten File name

I have made a media player with a listbox to add music files, like a playlist, but when I add a file it shows the entire folder/subfolder name with it.. This is the code I have for the add file

If OpenFile1.ShowDialog = Windows.Forms.DialogResult.OK And OpenFile1.FileName <> "" Then
            PlayerControl.URL = OpenFile1.FileName
            DurationTimer.Enabled = True
        End If
        ListBox1.Items.Add(OpenFile1.FileName)