WM_KEYDOWN and focus

[MasterDucky]

If I click on a button then it will keep the focus and I won't get any WM_KEYDOWN messages any more as long as I dont click outside and then back on the window.

What is the cause of this behaviour and how to avoid it?

The button:

    switch (message)
    {
    case WM_CREATE:
        CreateWindowExA(WS_EX_CLIENTEDGE,"BUTTON", "Play",
            WS_CHILD|WS_VISIBLE,
            20, 20, 80, 25, hWnd,
            (HMENU)IDB_PLAY, 0, NULL);