rem: volume_end = _music_volume;
add: volume_end = musicVolume;
context: FadeMusic (BYTE end_vol, SIZE TimeInterval){	DWORD TimeOut;	if (FadeTask)	{		volume_end = _music_volume;		TTotal = 1;		do			TaskSwitch ();		while (FadeTask);		TaskSwitch ();	}	if ((TTotal = TimeInterval) <= 0)		TTotal = 1; /* prevent divide by zero and negative fade */	volume_end = end_vol;			if (TTotal > 1 && (FadeTask = AssignTask (fade_task, 0,			"fade music")))	{		TimeOut = GetTimeCounter () + TTotal + 1;	}	else	{		SetMusicVolume (end_vol);		TimeOut = GetTimeCounter ();	}	return (TimeOut);}