Catching screen saver event with foreground application - c++

Question

I'm trying to catch the event when screen saver is turned off.
Actually, for now, I'm not getting any event of the screen saver (also not when it is launched).
I'm testing it when the application is in focus (foreground).
This is my code:
#include "stdafx.h"
#include "windows.h"
LRESULT CALLBACK wndProc(HWND hWnd, UINT msg, WPARAM wParam, LPARAM lParam);
static void RegisterWindowClasses() {
WNDCLASS wndClass;
memset(&wndClass, 0, sizeof(WNDCLASS));
wndClass.style = CS_HREDRAW | CS_VREDRAW;
wndClass.hInstance = NULL;
wndClass.lpszClassName = _T("Plugin-Video");
wndClass.hbrBackground = (HBRUSH) GetStockObject (DKGRAY_BRUSH);
wndClass.lpfnWndProc = wndProc;
RegisterClass(&wndClass);
}
LRESULT CALLBACK wndProc(HWND hWnd, UINT msg, WPARAM wParam, LPARAM lParam)
{
int wmId, wmEvent;
PAINTSTRUCT ps;
HDC hdc;
switch (msg)
{
case WM_SYSCOMMAND:
{
switch (LOWORD(wParam))
{
case SC_SCREENSAVE:
{
FILE *fl = fopen("this_is_a_event_test.txt","a");
fputs("SC_SCREENSAVE\n",fl);
fclose(fl);
}
break;
case SC_MONITORPOWER:
{
FILE *fl = fopen("this_is_a_event_test.txt","a");
fputs("SC_MONITORPOWER\n",fl);
fclose(fl);
}
break;
default:
{
}
}
}
break;
}
return DefWindowProc(hWnd, msg, wParam, lParam);
}
int _tmain(int argc, _TCHAR* argv[])
{
RegisterWindowClasses();
while(1){}
return 0;
}
Any suggestions?
Thanks!