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MCI_BREAK
 
        This MCI command message sets a break key for an MCI device.
        MCI supports this message directly rather than passing it to the
        device.
 
Parameters
        DWORD dwParam1
            The following flags apply to all devices:
 
            MCI_NOTIFY
                Specifies that MCI should post the MM_MCINOTIFY message
                when this command completes. The window to receive this
                message is specified in the dwCallback field of the data
                structure identified by lpBreak.
 
            MCI_WAIT
                Specifies that the break operation should finish before
                MCI returns control to the application.
 
            MCI_BREAK_KEY
                Indicates the nVirtKey field of the data structure
                identified by lpBreak specifies the virtual key code
                used for the break key. By default, MCI assigns
                CTRL+BREAK as the break key. This flag is required if
                MCI_BREAK_OFF is not specified.
 
            MCI_BREAK_HWND
                Indicates the hwndBreak field of the data structure
                identified by lpBreak contains a window handle which
                must be the current window in order to enable break
                detection for that MCI device. This is usually the
                application's main window. If omitted, MCI does not
                check the window handle of the current window.
 
            MCI_BREAK_OFF
                Used to disable any existing break key for the indicated
                device.
 
        DWORD dwParam2
            Specifies a far pointer to the MCI_BREAK_PARMS data
            structure.
 
Return value
        Returns zero if successful. Otherwise, it returns an MCI error
        code.
 
Comments
        You might have to press the break key multiple times to
        interrupt a wait operation. Pressing the break key after a
        device wait is broken can send the break to an application. If
        an application has an action defined for the virtual key code,
        then it can inadvertantly respond to the break. For example, an
        application using VK_CANCEL for an accelerator key can respond
        to the default CTRL+BREAK key if it is pressed after a wait is
        canceled.
 
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