-- Exit button for exiting a Neuron book
-- which also closes the browser window
to handle buttonClick
	linkDLL "user"
		WORD GetParent(WORD)
		WORD PostMessage(WORD, WORD, WORD, DWORD)
	end

	parentHWnd = parentHandle of mainWindow
	if parentHWnd <> 0
		-- ToolBook is running as a child of
		-- another process.
		-- Work our way up through the window
		-- hierarchy until we can find
		-- the top-level window
		while (GetParent(parentHWnd) <> 0)
			parentHWnd = GetParent(parentHWnd)
		end
		-- Now, close the top-level window
		WM_CLOSE = 16
		get PostMessage(parentHWnd, WM_CLOSE, 0, 0)
	end
end