DWORD GuiAcquireMutex(HANDLE hMutex, DWORD dwTimeout)
{
	if(hMutex == INVALID_HANDLE_VALUE)
		return ERROR_INVALID_HANDLE;
 
	DWORD     dwLastError = -1;

	while ( !g_bQuit && dwLastError != 0 )
	{
		dwLastError  = 0; // Success

		switch( WaitForSingleObject(hMutex, dwShortTimeout ) )
		{
		case WAIT_FAILED:
			Do_Set_LastError_Accordingly();
			break;
			
		case WAIT_TIMEOUT:
			dwLastError = ERROR_COUNTER_TIMEOUT;
			break;
		}
		// consider measure how long it takes ProcessEvents to finish,
		// if very quick, consider add a Sleep(500) or something like that
		// to avoid keeping CPU busy for nothing.
		topwin.ProcessEvents();
		if(TooSoon() )
		{
			Sleep (500);
		}
	}
	SetLastError (dwLastError) ;

	return dwLastError;
}