HttpWebRequest - GET & POST In Single Request

[Luk3r]

Hey everyone,
What I'm trying to do is pass credentials to a website to log into it. I'm able to get an authenticity token and also POST a token with login information. Unfortunately, my code for getting the token via HttpWebResponse gets a token in one stream and closes, so that token is different than the new token required in my HttpWebRequest stream. What I need to do is utilize HttpWebRequest to get a token, not close the stream, then POST data. I have yet to see an example on search engines that matches this criteria.

I got this from a forum. It grabs the token string:

    Private Function getToken()
        Dim r As HttpWebRequest = HttpWebRequest.Create("https://n135.meraki.com")
        Dim re As HttpWebResponse = r.GetResponse()
        Dim src As String = New StreamReader(re.GetResponseStream()).ReadToEnd()
        Return (GetBetween(src, "<input name=""authenticity_token"" type=""hidden"" value=""", """ /></div> "))
    End Function

This is the GetBetween() function used to grab the token within the getToken() function. Also from the same forum:

    Private Function GetBetween(ByVal Source As String, ByVal Str1 As String, ByVal Str2 As String, Optional ByVal Index As Integer = 0) As String
        Return (Regex.Split(Regex.Split(Source, Str1)(Index + 1), Str2)(0))
    End Function

This is the code in my button to try posting the login information to the web page:

    Private Sub Button3_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button3.Click
        Dim token As String = getToken()
        Dim postData As String = "" 'formatted token string with username and password goes here
        Dim tempCookies As New CookieContainer
        Dim encoding As New UTF8Encoding
        Dim byteData As Byte() = encoding.GetBytes(postData)
        Dim r As HttpWebRequest = DirectCast(HttpWebRequest.Create("https://n135.meraki.com"), HttpWebRequest)
 
        r.KeepAlive = True
        r.Method = "POST"
        r.CookieContainer = tempCookies
        r.ContentType = "application/x-www-form-urlencoded"
        r.Referer = "https://n135.meraki.com"
        r.UserAgent = "Mozilla/5.0 (Windows NT 6.2; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/30.0.1599.69 Safari/537.36"
        r.ContentLength = byteData.Length
 
        Dim re As Stream = r.GetRequestStream()
 
        re.Write(byteData, 0, byteData.Length)
        re.Close()
 
        Dim res As HttpWebResponse = DirectCast(r.GetResponse(), HttpWebResponse)
 
        tempCookies.Add(res.Cookies)
        loginCookies = tempCookies
 
        Dim src As String = New StreamReader(res.GetResponseStream()).ReadToEnd()
 
        If (src.Contains("Welcome")) Then
            loginCookies = tempCookies
            MsgBox("Success!")
        Else
            tempCookies = Nothing
            MsgBox("Failed.")
        End If
    End Sub

Any help would be greatly appreciated. I can convert from C# if someone has a working version or example similar to what I'm after. Thanks in advance!