DirectDraw

I have tried initializing DirectDraw with the following code :



private DirectX as DirectX7
private DirectDraw as DirectDraw7
private SurfaceDesc as DDSURFACEDESC2
private PrimarySurface as DirectDrawSurface7
private BackBuffer as DirectDrawSurface7



private Sub Main()
set DirectX = new DirectX7
set DirectDraw = DirectX.DirectDrawCreate("")

'error 1 :
DirectDraw.SetCooperativeLevel 0, DDSCL_FULLSCREEN Or DDSCL_ALLOWMODEX Or DDSCL_EXCLUSIVE

DirectDraw.SetDisplayMode 1024, 768, 16, 0, DDSDM_DEFAULT


With SurfaceDesc
.lFlags = DDSD_CAPS Or DDSD_BACKBUFFERCOUNT
.ddsCaps.lCaps = DDSCAPS_PRIMARYSURFACE Or DDSCAPS_COMPLEX Or DDSCAPS_FLIP
.lBackBufferCount = 1
End With

'error 2 :
set PrimarySurface = DirectDraw.CreateSurface(SurfaceDesc)
SurfaceDesc.ddsCaps.lCaps = DDSCAPS_BACKBUFFER
set BackBuffer = PrimarySurface.GetAttachedSurface(SurfaceDesc.ddsCaps)

set PrimarySurface = nothing
set DirectDraw = nothing
set DirectX = nothing
End Sub





When running it, the line just after "ERROR1" causes an "Invalid procedure call or argument" error.
The error does not occur only when I change the flag argument to DDSCL_NORMAL.
This, expectedly, causes an automation error (2005532447 - DDERR_NOEXCLUSIVEMODE ) in the line after "ERROR2".

Any help would be highly appreciated,

Gino