Авторизация на сайте - Visual Basic .NET (64711)

Imports System.Net
Imports System.IO
 
Public Class Form1
 
    Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
        Dim WC As New WebClient
        Dim Strings, Result As String
        Strings = WC.DownloadString("http://vkontakte.ru/login.php?op=1&email=" + TextBox1.Text + "&pass=" + TextBox2.Text + "&expire=0")
        WC.Dispose()
        Result = Pars(Strings, "<title>", "</title", 0)
        If Result = "В Контакте | Вход" Then
            MsgBox("Неверный логин или пароль")
        Else
            MsgBox(Result)
        End If
    End Sub
 
    Public Function Pars(ByRef strSource As String, ByRef strStart As String, ByRef strEnd As String, Optional ByRef startPos As Integer = 0) As String
        Dim iPos As Integer, iEnd As Integer, lenStart As Integer = strStart.Length
        Dim strResult As String
 
        strResult = String.Empty
        iPos = strSource.IndexOf(strStart, startPos)
        iEnd = strSource.IndexOf(strEnd, iPos + lenStart)
        If iPos <> -1 AndAlso iEnd <> -1 Then
            strResult = strSource.Substring(iPos + lenStart, iEnd - (iPos + lenStart))
        End If
        Return strResult
    End Function
End Class