when ever i execute this code it hangs ..any help how to troubleshoot the problem

Imports System.Net
Imports System.IO

Partial Class vbIPNexample
Inherits System.Web.UI.Page

Protected Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load
'Post back to either sandbox or live
Dim strSandbox As String = "https://www.sandbox.paypal.com/cgi-bin/webscr"
Dim strLive As String = "https://www.paypal.com/cgi-bin/webscr"
Dim req As HttpWebRequest = CType(WebRequest.Create(strSandbox), HttpWebRequest)

'Set values for the request back
req.Method = "POST"
req.ContentType = "application/x-www-form-urlencoded"
Dim Param() As Byte = Request.BinaryRead(HttpContext.Current.Request.ContentLength)
Dim strRequest As String = Encoding.ASCII.GetString(Param)
strRequest = strRequest + "&cmd=_notify-validate"
req.ContentLength = strRequest.Length

'for proxy
'Dim proxy As New WebProxy(New System.Uri("http://url:port#"))
'req.Proxy = proxy

'Send the request to PayPal and get the response
Dim streamOut As StreamWriter = New StreamWriter(req.GetRequestStream(), Encoding.ASCII)
Dim streamIn As StreamReader = New StreamReader(req.GetResponse().GetResponseStream())
Dim strResponse As String = streamIn.ReadToEnd()

If strResponse = "VERIFIED" Then
'check the payment_status is Completed
'check that txn_id has not been previously processed
'check that receiver_email is your Primary PayPal email
'check that payment_amount/payment_currency are correct
'process payment
ElseIf strResponse = "INVALID" Then
'log for manual investigation
'Response wasn't VERIFIED or INVALID, log for manual investigation
End If
End Sub
End Class

There are things like that

Packages single Double
Silver Number of rooms []50$ Number of rooms []100$Platinum Number of rooms []50$ Number of rooms []100$Gold Number of rooms []50$ Number of rooms []100$

user register on my website give his information like email,company,name and give above information and that information go for payment...

i need to tackle this ...can u help me!!if u further need to know let me know...