I am trying to parse out some xml data into some textboxes. This code works

Code:
	'xml request code hard coded textboxes.
 Dim path As String = DirectCast(Me.MdiParent, main_form).dir_path
        Dim XMLD As XmlDocument
        Dim XMLN As XmlNode

        Try
            XMLD = New XmlDocument()
            XMLD.Load(path + "\test2.xml")
            XMLN = XMLD.SelectSingleNode("/market_stat")
            min_ma_isogen_avg_buy.Text = XMLN.Item("avg_buy_price").InnerText
            min_ma_isogen_avg_sell.Text = XMLN.Item("avg_sell_price").InnerText
            min_ma_isogen_buy_vol.Text = XMLN.Item("total_buy_volume").InnerText
            min_ma_isogen_sell_vol.Text = XMLN.Item("total_sell_volume").InnerText
        Catch ex As Exception
            Debug.Print(ex.ToString())
        End Try
In the example the xml outputs to a hard coded text box. I would like to set this code up to be used on other textboxes too. So I set up something like this:

Code:
Private Sub update_prices(ByVal N1 As String, ByVal N2 As String, ByVal N3 As String, ByVal N4 As String, ByVal N5 As String, ByVal N6 As String)
        Dim path As String = DirectCast(Me.MdiParent, main_form).dir_path
        Dim XMLD As XmlDocument
        Dim XMLN As XmlNode

        Try
            XMLD = New XmlDocument()
            XMLD.Load(path + "\test2.xml")
            XMLN = XMLD.SelectSingleNode("/market_stat")
            N3 = XMLN.Item("avg_buy_price").InnerText
            N4 = XMLN.Item("avg_sell_price").InnerText
            N5 = XMLN.Item("total_buy_volume").InnerText
            N6 = XMLN.Item("total_sell_volume").InnerText
        Catch ex As Exception
            Debug.Print(ex.ToString())
        End Try


    End Sub
This does not work when called like this:
Code:
        update_prices(type_id, region_var, min_ma_isogen_avg_buy.Text, min_ma_isogen_avg_sell.Text, min_ma_isogen_buy_vol.Text, min_ma_isogen_sell_vol.Text)
If I put a stop in at the N6 line I can see all the N3-N5 have the correct value from the XML document but it does no display in the text boxes on the button click. FYI the N1 and N2 are tacked on the end of a URL and I am not using the URl in the example.

So why is it not outputting to the textboxes? I am not getting an error messages.

Thanks