Convert Vertical List to String Array

Private Sub ToolStripButton3_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles ToolStripButton3.Click
  myStr = String.Empty
  Dim arr() As String = txt.SelectedText.Split(Chr(10))
  For l = 0 To arr.Length - 1
    If arr(l).Length > 0 Then
      myStr &= Chr(34) & arr(l) & Chr(34)
      If l < arr.Length - 1 AndAlso arr(l).Length > 0 Then
        myStr &= ","
      End If
    End If
  Next
  txt.SelectedText = myStr
End Sub