Private Sub BackgroundWorker1_DoWork(ByVal sender As System.Object, ByVal e As System.ComponentModel.DoWorkEventArgs) Handles BackgroundWorker1.DoWork

        'Creating the request and getting the response
        Dim theResponse As HttpWebResponse
        Dim theRequest As HttpWebRequest
        Try 'Checks if the file exist

            theRequest = WebRequest.Create(Me.txtFileName.Text)
            theResponse = theRequest.GetResponse
        Catch ex As Exception

            MessageBox.Show("An error occurred while downloading file. Possibe causes:" & ControlChars.CrLf & _
                            "1) File doesn't exist" & ControlChars.CrLf & _
                            "2) Remote server error", "Error", MessageBoxButtons.OK, MessageBoxIcon.Error)

            Dim cancelDelegate As New DownloadCompleteSafe(AddressOf DownloadComplete)

            Me.Invoke(cancelDelegate, True)

            Exit Sub
        End Try
        Dim length As Long = theResponse.ContentLength 'Size of the response (in bytes)

        Dim safedelegate As New ChangeTextsSafe(AddressOf ChangeTexts)
        Me.Invoke(safedelegate, length, 0, 0, 0) 'Invoke the TreadsafeDelegate

        Dim writeStream As New IO.FileStream(Me.whereToSave, IO.FileMode.Create)

        'Replacement for Stream.Position (webResponse stream doesn't support seek)
        Dim nRead As Integer

        'To calculate the download speed
        Dim speedtimer As New Stopwatch
        Dim currentspeed As Double = -1
        Dim readings As Integer = 0

        Do

            If BackgroundWorker1.CancellationPending Then 'If user abort download
                Exit Do
            End If

            speedtimer.Start()

            Dim readBytes(4095) As Byte
            Dim bytesread As Integer = theResponse.GetResponseStream.Read(readBytes, 0, 4096) ******AYUDA********

            nRead += bytesread
            Dim percent As Short = (nRead * 100) / length

            Me.Invoke(safedelegate, length, nRead, percent, currentspeed)

            If bytesread = 0 Then Exit Do

            writeStream.Write(readBytes, 0, bytesread)

            speedtimer.Stop()

            readings += 1
            If readings >= 5 Then 'For increase precision, the speed it's calculated only every five cicles
                currentspeed = 20480 / (speedtimer.ElapsedMilliseconds / 1000)
                speedtimer.Reset()
                readings = 0
            End If
        Loop

        'Close the streams
        theResponse.GetResponseStream.Close()
        writeStream.Close()

        If Me.BackgroundWorker1.CancellationPending Then

            IO.File.Delete(Me.whereToSave)

            Dim cancelDelegate As New DownloadCompleteSafe(AddressOf DownloadComplete)

            Me.Invoke(cancelDelegate, True)

            Exit Sub

        End If

        Dim completeDelegate As New DownloadCompleteSafe(AddressOf DownloadComplete)

        Me.Invoke(completeDelegate, False)

    End Sub

theResponse.GetResponseStream.Read(readBytes, 0, 4096) ******AYUDA********

insertamos el video
<script type="text/javascript" src="swfobject.js"></script>
 <div id="ytapiplayer">
   Se necesita una versión de Flash Player superior a 8
	y javascript, para ver este video.
 </div>

 <script type="text/javascript">

   var params = { allowScriptAccess: "always" };
   var atts = { id: "myytplayer" };
   swfobject.embedSWF("http://www.youtube.com/v/VIDEO_ID&enablejsapi=1&playerapiid=ytplayer",
                      "ytapiplayer", "425", "356", "8", null, null, params, atts);
 </script>



 function onYouTubePlayerReady(playerId) {
      ytplayer = document.getElementById("myytplayer");
    }






</script>

<a href="javascript:ytplayer.playVideo()">Reproducir</a>