int instance_create(int owner_id, const char *name, enum instance_owner_type type) {
	struct map_session_data *sd = NULL;
	unsigned short *icptr = NULL;
	struct party_data *p = NULL;
	struct guild *g = NULL;
	short *iptr = NULL;
	int i, j;
	
	switch ( type ) {
		case IOT_NONE:
			break;
		case IOT_CHAR:
			if( ( sd = iMap->id2sd(owner_id) ) == NULL ) {
				ShowError("instance_create: character %d not found for instance '%s'.\n", owner_id, name);
				return -2;
			}
			iptr = sd->instance;
			icptr = &sd->instances;
			break;
		case IOT_PARTY:
			if( ( p = party->search(owner_id) ) == NULL ) {
				ShowError("instance_create: party %d not found for instance '%s'.\n", owner_id, name);
				return -2;
			}
			iptr = p->instance;
			icptr = &p->instances;
			break;
		case IOT_GUILD:
			if( ( g = guild->search(owner_id) ) == NULL ) {
				ShowError("instance_create: guild %d not found for instance '%s'.\n", owner_id, name);
				return -2;
			}
			iptr = g->instance;
			icptr = &g->instances;
			break;
		default:
			ShowError("instance_create: unknown type %d for owner_id %d and name %s.\n", type,owner_id,name);
			return -1;
	}
	
	if( type != IOT_NONE && *icptr ) {
		ARR_FIND(0, *icptr, i, strcmp(instances[iptr[i]].name,name) == 0 );
		if( i != *icptr )
			return -4;/* already got this instance */
	}
		
	ARR_FIND(0, instance->instances, i, instances[i].state == INSTANCE_FREE);
		
	if( i == instance->instances )
		RECREATE(instances, struct instance_data, ++instance->instances);

	instances[i].state = INSTANCE_IDLE;
	instances[i].id = i;
	instances[i].idle_timer = INVALID_TIMER;
	instances[i].idle_timeout = instances[i].idle_timeoutval = 0;
	instances[i].progress_timer = INVALID_TIMER;
	instances[i].progress_timeout = 0;
	instances[i].users = 0;
	instances[i].map = NULL;
	instances[i].num_map = 0;
	instances[i].owner_id = owner_id;
	instances[i].owner_type = type;
	instances[i].vars = idb_alloc(DB_OPT_RELEASE_DATA);

	safestrncpy( instances[i].name, name, sizeof(instances[i].name) );
	
	if( type != IOT_NONE ) {
		ARR_FIND(0, *icptr, j, iptr[j] == -1);
		if( j == *icptr ) {
			switch( type ) {
				case IOT_CHAR:
					RECREATE(sd->instance, short, ++*icptr);
					sd->instance[sd->instances-1] = i;
					break;
				case IOT_PARTY:
					RECREATE(p->instance, short, ++*icptr);
					p->instance[p->instances-1] = i;
					break;
				case IOT_GUILD:
					RECREATE(g->instance, short, ++*icptr);
					g->instance[g->instances-1] = i;
					break;
			}
		} else
			iptr[j] = i;
	}
	
	clif->instance(i, 1, 0); // Start instancing window
	return i;
}