problem with XML reader

[Naiven]

i've been working on a project in vb and need some help i'm trying to read xml but i dont know what to do with one of the variables

 Function SearchAuction(ByVal TradeID As Integer, ByVal PlayerID As Integer) As Integer
        Dim settings As New XmlReaderSettings()
        settings.IgnoreComments = True
        Dim SearchURL As String = Path.Combine(Request.PhysicalApplicationPath, "URL")
        Using reader As XmlReader = XmlReader.Create(SearchURL, settings)
            While (reader.Read())
                If (reader.NodeType = XmlNodeType.Element And "ResourceID" = PlayerID) Then
                    TradeID = reader.LocalName
                End If
            End While
        End Using
        rtbNews.Text = (rtbNews.Text & Environment.NewLine & "The TradeID " & TradeID & "was found")
    End Function
 

the line

Path.Combine(Request.PhysicalApplicationPath, "URL")

is the problem it keeps coming up with " 'Request' is not declared"
i do not know what to declare it as can anyone help?