TreeView Directory Structure location

[CliffE]

Imports System
Imports System.IO

Imports Telerik.Web.UI

Namespace Telerik.Web.Examples.TreeView.DirectoryStructure

    Partial Public Class DefaultVB
        Inherits System.Web.UI.Page

        Private ReadOnly KnownExtensions As String() = New String() {"aspx", "asmx", "cs", "vb", "xml", "ascx", _
         "jpg", "png", "gif", "html", "pdf"}

        Private Sub BindTreeToDirectory(ByVal virtualPath As String, ByVal parentNode As RadTreeNode)
            Dim physicalPath As String = Server.MapPath(virtualPath)
            Dim directories As String() = Directory.GetDirectories(physicalPath)
            For Each directory As String In directories
                Dim node As New RadTreeNode(Path.GetFileName(directory))
                node.Value = virtualPath + "/" + Path.GetFileName(directory)
                node.ImageUrl = "~/TreeView/Img/Vista/folder.png"
                node.ExpandMode = TreeNodeExpandMode.ServerSideCallBack
                parentNode.Nodes.Add(node)
            Next

            Dim files As String() = Directory.GetFiles(physicalPath)
            For Each file As String In files
                Dim node As New RadTreeNode(Path.GetFileName(file))
                Dim extension As String = Path.GetExtension(file).ToLower().TrimStart("."c)

                If Array.IndexOf(KnownExtensions, extension) > -1 Then
                    node.ImageUrl = "~/TreeView/Img/Vista/" + extension + ".png"
                Else
                    node.ImageUrl = "~/TreeView/Img/Vista/unknown.png"
                End If

                parentNode.Nodes.Add(node)
            Next
        End Sub

        Protected Sub Page_Load(ByVal sender As Object, ByVal e As EventArgs) Handles Me.Load
            If Not Page.IsPostBack Then
                Dim rootNode As New RadTreeNode("8000")
                rootNode.Value = "2009"
                rootNode.ImageUrl = "~/TreeView/Img/Vista/folder.png"
                rootNode.Expanded = True
                rootNode.SelectedImageUrl = True
                rootNode.ExpandMode = TreeNodeExpandMode.ServerSideCallBack
                RadTreeView1.Nodes.Add(rootNode)
            End If
        End Sub

        Protected Sub RadTreeView1_NodeExpand(ByVal sender As Object, ByVal e As RadTreeNodeEventArgs)
            BindTreeToDirectory(e.Node.Value, e.Node)
        End Sub

    End Class

End Namespace

I am having issues pulling folders/files from a server share into RadTreeView.  Can someone look at my vb code and help?