WM_CAP_DRIVER_CONNECT Return value

[DCCD]

Hi everybody, I have some code for acquiring webcam image using [WM_CAP_DRIVER_CONNECT], Unfortunately [WM_CAP_DRIVER_CONNECT] return nothing.

I have been reading about [WM_CAP_DRIVER_CONNECT] on MSDN LINK, they said

Returns TRUE if successful or FALSE if the specified capture driver cannot be connected to the capture window.

So my question is, How can I get returned value from [WM_CAP_DRIVER_CONNECT].?

Any help would be greatly appreciated.