private void checkTimeFields(Time time) {
		if (time.getIdActivity() < 0) {
			AlertMessages.emptyTimeField(timeDialog, AlertMessages.ACTIVITY_ID);
		} else if (time.getStartTime() == null) {
			AlertMessages.emptyTimeField(timeDialog, AlertMessages.START_TIME);
		} else if (time.getEndTime() == null) {
			AlertMessages.emptyTimeField(timeDialog, AlertMessages.END_TIME);
		} else if (time.getDuration() < MINIMUM_TIME_DURATION) {
			AlertMessages.emptyTimeField(timeDialog, AlertMessages.DURATION);
		} else {
			AlertMessages.emptyTimeField(timeDialog, AlertMessages.OTHER_PROBLEM);
		}
	}