Dim Host As String = "tuservidor"
        Dim con As New OleDb.OleDbConnection("Provider=SQLOLEDB; Data Source=" & Host & "; Initial Catalog=TuBase; integrated security=SSPI; persist security info=True;")

        Dim da As OleDb.OleDbDataAdapter
        Dim dtb As DataTable
        Dim a As Integer

        Dim Codigo As String

        da = New OleDb.OleDbDataAdapter("select * from dimtempcustomer where dimt_padre=''", con)
        dtb = New DataTable
        da.Fill(dtb)

        TreeView1.Nodes.Add(Trim("[" & dtb.Rows(a)("dimt_codigo").ToString) & "]-- " & Trim(dtb.Rows(0)("dimt_descripcion").ToString))
        Codigo = Trim(dtb.Rows(0)("dimt_codigo").ToString)

Dim Host As String = "tuservidor"
        Dim con As New OleDb.OleDbConnection("Provider=SQLOLEDB; Data Source=" & Host & "; Initial Catalog=TuBase; integrated security=SSPI; persist security info=True;")

        Dim da As OleDb.OleDbDataAdapter
        Dim dtb As DataTable
        Dim a, i As Integer
        Static Cargados As String

        Dim Codigo, Descripcion As String
        Dim parte = Split(TreeView1.SelectedNode.Text, "]-- ")
        Dim flag = Split(Cargados, "--")

        Me.Cursor = Cursors.WaitCursor
        Codigo = Trim(Mid(parte(0), 2))

        For i = 1 To UBound(flag)
            If Codigo = flag(i) Then
                Me.Cursor = Cursors.Default
                Exit Sub
            End If
        Next
        Cargados += "--" & Codigo
        da = New OleDb.OleDbDataAdapter("select * from dimtempcustomer where dimt_padre='" & Codigo & "'", con)
        dtb = New DataTable
        da.Fill(dtb)

        For a = 0 To dtb.Rows.Count - 1
            Codigo = Trim(dtb.Rows(a)("dimt_codigo").ToString)
            Descripcion = Trim(dtb.Rows(a)("dimt_descripcion").ToString)

            TreeView1.SelectedNode.Nodes.Add("[" & Codigo & "]-- " & Descripcion)
        Next
        TreeView1.SelectedNode.Expand()
        Me.Cursor = Cursors.Default