HTTPWebRequest Posting Multiple Files

[skibum019]

I am having problems with posting multiple files to our customer using a ssl URL with a certificate. I seem to be able to send one file to them at a time (with some unknown interval of time between them), but I am unable to send files in succession when sending multiple files. I have spoken with their team, and supposedly we are able to use the same connection for multiple files and/or use parallel sessions. Below is the code that actually does the "sending" of the file. I call the code from another procedure that is looping through a list of files to send. These are XML files that we have generated and the file structure is fine with all of the files we attempt to send. Any help would be much appreciated.

    Public Sub SendData2Customer(ByVal strURL As String, ByVal strFileName As String)
        Dim webReq As HttpWebRequest
        Dim i As Integer, mySTR As String
        Dim mystore As New X509Store(StoreLocation.CurrentUser)
        Dim certificate As X509Certificate2
        Dim myProxy As New WebProxy(proxyAddress & ":" & proxyPort)
        Dim myRdr As StreamReader
        Dim myWrtr As StreamWriter
        If UserCert = "" Then
            MsgBox("You must specify a SSL Certificate to use in the transmission.  " & _
                "Go to the options page and specify an appropriate certificate.", MsgBoxStyle.Exclamation, _
                "Certificate Missing")
            returnMsg = "ERROR,NO CERT,NO RESPONSE"
            Exit Sub
        End If
        Try
            mystore.Open(OpenFlags.ReadOnly)
            i = 0
            For Each certificate In mystore.Certificates
                If certificate.Subject.ToString = UserCert Then
                    Exit For
                End If
                i = i + 1
            Next
            certificate = mystore.Certificates(i)

            i = 0 : mySTR = ""

            webReq = HttpWebRequest.Create(strURL)
            webReq.KeepAlive = False
            webReq.Method = "POST"
            webReq.AllowAutoRedirect = True
            webReq.ContentType = "text/xml"
            webReq.Timeout = 100000
            webReq.AllowWriteStreamBuffering = True

            System.Net.ServicePointManager.SecurityProtocol = System.Net.SecurityProtocolType.Ssl3
            If UseProxy = True Then
                myProxy.Credentials = New NetworkCredential(proxyUser, proxyPassword, proxyDomain)
                webReq.Proxy = myProxy
            End If
            webReq.ClientCertificates.Add(certificate)
            'Debug.Print(webReq.ClientCertificates.Count)
            myRdr = New StreamReader(strFileName)
            myWrtr = New StreamWriter(webReq.GetRequestStream)
            myWrtr.Write(myRdr.ReadToEnd)
            myWrtr.Close()
            myRdr.Close()
            myRdr = Nothing
            myWrtr = Nothing


            Dim myRsp As HttpWebResponse = Nothing
            myRsp = webReq.GetResponse
            If myRsp IsNot Nothing Then
                Dim mySR As New StreamReader(myRsp.GetResponseStream)

                returnMsg = myRsp.StatusCode & "," & _
                    myRsp.StatusDescription & "," & mySR.ReadToEnd
            Else
                returnMsg = "ERROR,NO RESPONSE FROM SERVER,NO RESPONSE"
            End If
            If myRsp IsNot Nothing Then
                myRsp.Close()
                myRsp = Nothing
            End If
            webReq.Abort()
        Catch we As WebException
            MsgBox("error Occurred: " & we.Message)
            returnMsg = "ERROR," & we.Message & "," & we.GetBaseException.ToString
            If we.Response IsNot Nothing Then
                we.Response.Close()
            End If
            myRdr = Nothing
            myWrtr = Nothing
        End Try
    End Sub