Fullscreen window

[Cheffix]

Hi guys!
I´ve got a problem!
So
I made a fullscreen window with

CreateWindowEx(NULL,
                     L"WindowClass",
                     L"Direct3D Window",
                     WS_EX_TOPMOST | WS_POPUP,    // fullscreen values
                     200, 0,    // the starting x and y positions should be 0
	             WIDTH,HEIGHT,
                     NULL,
                     NULL,
                     GetModuleHandle(NULL),
                     NULL);

And i made an attribute bool bActivated
Everytime the window got deactivated (shift to background) i want to set bActivated to false and otherwise set to true.
normally i would use WM_SIZE but because it is a fullscreen window this doesnt work
what message could i use instead???
Please help me!! I`m desperate!!

Thanks
Peter

[freddie1]

I'd put debug output statements into several message handlers such as for WM_SETFOCUS, WM_KILLFOCUS, WM_ACTIVATE and see which ones work for the scenerio you are coding for.