Capture Video from WebCam in VB.NET

I would like to capture video from a webcam in VB.Net.  The following sourcecode displays the video correctly:

Private Sub cmdCapture_Click(ByVal eventSender As System.Object, ByVal eventArgs As System.EventArgs) Handles cmdCapture.Click
Dim temp As Integer      
hwdc = capCreateCaptureWindow("Dixanta Vision System", ws_child Or ws_visible, 0, 0, 320, 240, Picture1.Handle.ToInt32, 0)
If (hwdc <> 0) Then
   temp = SendMessage(hwdc, wm_cap_driver_connect, 0, 0)
   temp = SendMessage(hwdc, wm_cap_set_preview, 1, 0)
   temp = SendMessage(hwdc, WM_CAP_SET_PREVIEWRATE, 30, 0)
   startcap = True
Else
   MsgBox("No Webcam found")
End If
End Sub

I have added the code temp = SendMessage(hwdc, WM_CAP_SEQUENCE, 0, 0L)
This does create a video file - however there is no video, only sound.

Can you help me to get this snippet to work - or do you have other full source code that you can share?