Function GetHtmlPageSource(ByVal url As String, Optional ByVal username As _
    String = Nothing, Optional ByVal password As String = Nothing) As String
    Dim st As System.IO.Stream
    Dim sr As System.IO.StreamReader

    Try
        ' make a Web request
        Dim req As System.Net.WebRequest = System.Net.WebRequest.Create(url)
        ' if the username/password are specified, use these credentials
        If Not username Is Nothing AndAlso Not password Is Nothing Then
            req.Credentials = New System.Net.NetworkCredential(username, _
                password)
        End If
        ' get the response and read from the result stream
        Dim resp As System.Net.WebResponse = req.GetResponse
        st = resp.GetResponseStream
        sr = New System.IO.StreamReader(st)
        ' read all the text in it
        Return sr.ReadToEnd
    Catch ex As Exception
        Return ""
    Finally
        ' always close readers and streams
        sr.Close()
        st.Close()
    End Try
End Function