DestroyWindow behavior

Hi,

I am getting strange result while executing below code.

LRESULT CALLBACK WndProc(HWND hWnd, UINT message, WPARAM wParam, LPARAM lParam)
{
    int wmId, wmEvent;
    PAINTSTRUCT ps;
    HDC hdc;
    TCHAR szHello[MAX_LOADSTRING];
    LoadString(hInst, IDS_HELLO, szHello, MAX_LOADSTRING);

    switch (message) 
    {
        case WM_COMMAND:
            wmId    = LOWORD(wParam); 
            wmEvent = HIWORD(wParam); 
            // Parse the menu selections:
            switch (wmId)
            {
                case IDM_ABOUT:
                   DialogBox(hInst, (LPCTSTR)IDD_ABOUTBOX, hWnd, (DLGPROC)About);
                   break;
                case IDM_EXIT:
                   DestroyWindow(hWnd);
                   break;
                default:
                   return DefWindowProc(hWnd, message, wParam, lParam);
            }
            break;
        case WM_PAINT:
            hdc = BeginPaint(hWnd, &ps);
            // TODO: Add any drawing code here...
            RECT rt;
            GetClientRect(hWnd, &rt);
            DrawText(hdc, szHello, strlen(szHello), &rt, DT_CENTER);
            EndPaint(hWnd, &ps);
            break;
        case WM_LBUTTONDOWN:
            ::PostMessage(hWnd, WM_USER + 1, 0, 0);
            ::PostMessage(hWnd, WM_USER + 1, 0, 0);
            ::PostMessage(hWnd, WM_USER + 1, 0, 0);
            ::DestroyWindow(hWnd);
            break;
        case (WM_USER + 1):
            OutputDebugString("\n(WM_USER + 1)");
            break;
        case WM_DESTROY:
            OutputDebugString("\n(WM_DESTROY)");
            break;
        default:
            return DefWindowProc(hWnd, message, wParam, lParam);
   }
   return 0;
}

When window gets WM_LBUTTONDOWN, I am sending 3 User messages and then I am calling ::DestroyWindow(hWnd). I am getting WM_DESTROY message immediately.

Now my question is that after destroying window, what happens for the pending messages?

In my application sometimes I am getting WM_USER message even if i have destroyed the window. I search in MSDN for DestroyWindow(), but I did not understand how WINDPROC for destryed window can be called after DestroyWindow(). Please Help to understand the exact behavior.

Regards,

Ankit