Populating Treeview from DB - Stops at 3rd level

[ErikKoz]

This is probably more of a beginner issue, but Im trying to populate a treeview based off the Northwind Database. The Top level is a list of countries, second level is a list of customers from that country, and 3rd level is supposed to be orderids from that country but it isnt populating. I know its stopping at my 'FillOrderIDs' but I cant seem to figure out why. I appreciate any advice,

Private Sub FillCountries()
    Dim tcountry As String
    Dim tnode As TreeNode
    Dim tCountryTable As NorthwindDataSet.CountriesDataTable
    tCountryTable = Me.CountriesTableAdapter.GetCountriesData
    For Each trow As NorthwindDataSet.CountriesRow In tCountryTable

        tcountry = trow.Country
        tnode = New TreeNode
        tnode.Name = "Country"
        tnode.Text = tcountry
        Me.TreeView1.TopNode.Nodes.Add(tnode)
        FillCompanyNames(tcountry, tnode)
    Next
End Sub

Private Sub FillCompanyNames(ByVal country As String, ByVal parentnode As TreeNode)
    Dim tCompany As String
    Dim tnode As TreeNode
    Dim CustTable As NorthwindDataSet.CompanyNamesDataTable
    CustTable = Me.CompanyNamesTableAdapter.GetCustomersByCountry(country)

    For Each trow As NorthwindDataSet.CompanyNamesRow In CustTable
        tCompany = trow.CompanyName
        tnode = New TreeNode
        tnode.Name = "CompanyName"
        tnode.Text = trow.CompanyName
        tnode.Tag = trow.CompanyName
        parentnode.Nodes.Add(tnode)
        FillOrderIDs(tCompany, tnode)
    Next

End Sub

Private Sub FillOrderIDs(ByVal orderid As String, ByVal parentnode As TreeNode)
    Dim tnode As TreeNode
    Dim OrdTable As NorthwindDataSet.OrderIdsDataTable
    OrdTable = Me.OrderIdsTableAdapter.GetOrderIds(CompanyName)

    For Each trow As NorthwindDataSet.OrderIdsRow In OrdTable
        tnode = New TreeNode
        tnode.Name = "OrderID"
        tnode.Text = trow.OrderID
        tnode.Tag = trow.OrderID
        parentnode.Nodes.Add(tnode)
    Next
End Sub

Private Sub btnDisplay\_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnDisplay.Click
    TreeView1.Nodes.Add("Countries")
    FillCountries()
End Sub