how can i use one connection to upload multiple files in vb.net

i've this application that reads multiple files from a folder and upload them to the server..it works fine but when it wants to upload each file, it creates a connection, upload the file and closes the connection. it does the same thing for all the files over and over again. i want a situation where it creates just one connection, upload all the files and close the connection. please any help will be appreciated, i searched everywhere but couldn't find any help. below is my code

Code:

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Imports System.IO
Imports System.Net

Public Class DemoFTPServerApp

Dim _Filename As String
Dim _UploadPath As String
Dim f As String


Public Sub LoadFiles(_User As String, _Password As String, _Path As String)
    Dim _MyArraylist As New ArrayList
    Dim FolderPath As String = "C:\Users\Desktop\files"



    Dim finfo As New DirectoryInfo(FolderPath)
    For Each fi In finfo.GetFiles("*.txt")
        _MyArraylist.Add(fi.FullName) 'full path only
        _Filename = fi.FullName
        f = fi.ToString()
        _UploadPath = _Path & f


      Try
      Dim request As FtpWebRequest = DirectCast(WebRequest.Create(New Uri(_UploadPath)), FtpWebRequest)
            request.Method = WebRequestMethods.Ftp.UploadFile
            request.Credentials = New NetworkCredential(_User, _Password)
            request.UseBinary = True
            request.UsePassive = False
            request.KeepAlive = True
            request.ConnectionGroupName = "company name"
            request.ServicePoint.ConnectionLimit = 4
            request.ServicePoint.CloseConnectionGroup("company name")


            Dim buffer(1023) As Byte
            Dim bytesIn As Long = 1

            Dim filepath As System.IO.FileInfo = New System.IO.FileInfo(_Filename)
            Dim _FileStream As System.IO.FileStream = filepath.OpenRead()
            Dim _Stream As System.IO.Stream = request.GetRequestStream


            Do Until bytesIn < 1
                bytesIn = _FileStream.Read(buffer, 0, 1024)
                If bytesIn > 0 Then
                    _Stream.Write(buffer, 0, bytesIn)

                End If
            Loop

            _Stream.Close()
            _Stream.Dispose()
            _FileStream.Close()
            _FileStream.Dispose()
        Catch ex As Exception
            MessageBox.Show(ex.Message)
        End Try
    Next

    MessageBox.Show("File Succesfully uploaded!")

End Sub

Private Sub btnUploadFile_Click(sender As Object, e As EventArgs) Handles btnUploadFile.Click

  LoadFiles("username", "password", "ftp://ftpsite.com/")

End Sub

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