NullReferenceException while parsing XML

I'm trying to make use of the Wikipedia API for a simple school project. I'm trying to parse this URL using WebRequest to download the source and XElement to parse the data. I'm using the following code

Dim request As WebRequest = WebRequest.Create("http://bg.wikipedia.org/w/api.php?action=opensearch&format=xml&search=" + text)
request.Credentials = CredentialCache.DefaultCredentials
Dim reader As New StreamReader(request.GetResponse().GetResponseStream())
Dim elm As XElement = XElement.Load(reader)
If elm IsNot Nothing Then

    Dim a As XElement = elm.Element("Section")

    For Each page As Object In a.Elements("Item")
        Dim title = page.Element("Text").Value
        Dim url = page.Element("image").Value

    Next
End If 

but I'm getting NullReferenceException at the beginning of For Each. Is this the right way to parse XML document in vbNET?

Try this

    If elm IsNot Nothing Then
        For Each xe As XElement In elm.Nodes
            If xe.Name.LocalName = "Section" Then
                For Each sxe As XElement In xe.Nodes
                    If sxe.Name.LocalName = "Item" Then
                        Dim title As String
                        Dim url As String
                        For Each n As XElement In sxe.Nodes
                            If n.Name.LocalName = "Text" Then
                                title = n.Value.ToString
                            ElseIf n.Name.LocalName = "Image" Then
                                url = n.@source
                            End If
                        Next
                        Debug.WriteLine(title)
                        Debug.WriteLine(url)
                    End If
                Next
            End If
        Next
    End If

This can probably be simplified using LINQ, but it is a start.