Turn Undead skill mod

[pajodex]

Hi,

How can I make Turn Undead damage to demi-humans? No instant kill but just damages them then adds SC_CURSE for 10% chance?

skill.cpp

case PR_TURNUNDEAD:
			{
				struct status_data *tstatus = status_get_status_data(target);
				if (!battle_check_undead(tstatus->race, tstatus->def_ele))
					return USESKILL_FAIL_MAX;
			}
			break;

Thanks in advance