TCHAR szDebug [100];
   __int64 liTicksPerSec64;
   __int64 liBeginTime64;
   __int64 liEndTime64;

   QueryPerformanceFrequency ((LARGE_INTEGER*)&liTicksPerSec64);

   QueryPerformanceCounter ((LARGE_INTEGER*)&liBeginTime64);
   // do some stuff...
   QueryPerformanceCounter ((LARGE_INTEGER*)&liEndTime64);

   itus = CalcMicroSecInterval (liTicksPerSec64,
                                liBeginTime64, 
                                liEndTime64);
   wsprintf (szDebug, "Time to do stuff: %dms", itus/1000);
   OutputDebugString (szDebug);


// Helper function:


int CalcMicroSecInterval (__int64 liTicksPerSec64,
                    __int64 liStart64, 
                    __int64 liEnd64) 
{
   double dTicksPerUs, dInterval;
   
   __int64 iIntTicks64;
   int iInterval ;
   int iTicksIn;

   dTicksPerUs  = (double)liTicksPerSec64 / (double)1000000.0;

   if (liEnd64 > liStart64)
      iIntTicks64  = liEnd64 - liStart64;
   else
      iIntTicks64  = liStart64 - liEnd64;
   
   iTicksIn     = (int) iIntTicks64;
   dInterval    = ((double) iIntTicks64) / dTicksPerUs;
   iInterval    = (int) dInterval;

   return iInterval;
}