Filter a search? *[resolved]*

[ProgrammerJon]

Private Sub MenuItem5_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MenuItem5.Click
        ' make a reference to a directory
        Dim di As New IO.DirectoryInfo("c:/")
        Dim diArr As IO.DirectoryInfo() = di.GetDirectories()
        Dim diar1 As IO.FileInfo() = di.GetFiles()




        ' list the names of all the subdirectories in the specified directory
        Dim dri As IO.DirectoryInfo

        'BeginUpdate method freezes painting while you add items
        ListBox1.BeginUpdate()
        For Each dri In diArr
            ListBox2.Items.Add(dri)
        Next

        'EndUpdate resumes painting of listbox
        ListBox1.EndUpdate()

        'list the names of all files in the specified directory
        Dim dra As IO.FileInfo
        For Each dra In diar1
            ListBox1.Items.Add(dra)
        Next
        Dim r As String()
        r = IO.Directory.GetDirectories("c:/")
        ListBox1.DataSource = r

    End Sub

How can I make it so that this program only returns files that have .mp3 extension?