VB.NET สอบถามวิธี navigate WebBrowser1.Navigate ไป URL พร้อมกับ CookieContainer

Imports System.Net
Imports System.Text
Imports System.IO


Public Class Form1

    Dim logincookie As CookieContainer


    Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click


        Dim postData As String = "memberid=" & TextBox1.Text & "&userid=undefined&password=" & TextBox2.Text & "&captcha=undefined"
        Dim tempCookies As New CookieContainer
        Dim encoding As New UTF8Encoding
        Dim byteData As Byte() = encoding.GetBytes(postData)

        Dim postReq As HttpWebRequest = DirectCast(WebRequest.Create("http://www.gamagic.com/user/login_chk"), HttpWebRequest)
        postReq.Method = "POST"
        postReq.KeepAlive = True
        postReq.CookieContainer = tempCookies
        postReq.ContentType = "application/x-www-form-urlencoded"
        postReq.Referer = "http://www.gamagic.com/user/login_chk"
        postReq.UserAgent = "Mozilla/5.0 (Windows; U; Windows NT 6.1; ru; rv:1.9.2.3) Gecko/20100401 Firefox/4.0 (.NET CLR 3.5.30729)"
        postReq.ContentLength = byteData.Length

        Dim postreqstream As Stream = postReq.GetRequestStream()
        postreqstream.Write(byteData, 0, byteData.Length)
        postreqstream.Close()
        Dim postresponse As HttpWebResponse

        postresponse = DirectCast(postReq.GetResponse(), HttpWebResponse)
        tempCookies.Add(postresponse.Cookies)
        logincookie = tempCookies
        
        Dim postreqreader As New StreamReader(postresponse.GetResponseStream())

        Dim thepage As String = postreqreader.ReadToEnd

        RichTextBox1.Text = thepage

        System.Threading.Thread.Sleep(1000)
        WebBrowser1.Navigate("http://www.gamagic.com", False, byteData, "")
        

    End Sub

    Private Sub Button2_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button2.Click
        WebBrowser1.DocumentText = RichTextBox1.Text
    End Sub

    Private Sub Button4_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button4.Click
        WebBrowser1.DocumentText = RichTextBox2.Text

    End Sub

    Private Sub Button3_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button3.Click

        Dim request As HttpWebRequest = DirectCast(WebRequest.Create("http://www.gamagic.com/forum/forum.php?mod=forumdisplay&fid=122"), HttpWebRequest)
        request.CookieContainer = logincookie
        Dim response As HttpWebResponse = DirectCast(request.GetResponse(), HttpWebResponse)
        Dim reader As New StreamReader(response.GetResponseStream())
        Dim theusercp As String = reader.ReadToEnd

        RichTextBox2.Text = theusercp



        WebBrowser1.Navigate("http://www.gamagic.com/forum/forum.php?mod=forumdisplay&fid=122")


    End Sub

 
    Private Sub Button5Home_Click(sender As Object, e As EventArgs) Handles Button5.Click
        WebBrowser1.Navigate("http://www.gamagic.com")

    End Sub

    Private Sub Button7Forward_Click(sender As Object, e As EventArgs) Handles Button7.Click
        WebBrowser1.GoForward()
    End Sub

    Private Sub Button6Back_Click(sender As Object, e As EventArgs) Handles Button6.Click
        WebBrowser1.GoBack()
    End Sub
End Class