Belt -> add attr_rare?

[Necro 76]

Hi guys, i set index for belt system: 

	if (GetType() == ITEM_BELT)
	{
		return ATTRIBUTE_SET_BELT;
	}

but when i use item(71051)

then sysser write me this:

number_ex: number(): first argument is bigger than second argument 0 -> -1, item_attribute.cpp 405

Here is the item_attribute

bool CItem::AddRareAttribute()
{
	int count = GetRareAttrCount();

	if (count >= 1)
		return false;

	int pos = count + 5;
	TPlayerItemAttribute & attr = m_aAttr[pos];

	int nAttrSet = GetAttributeSetIndex();
	std::vector<int> avail;

	for (int i = 0; i < MAX_APPLY_NUM; ++i)
	{
		const TItemAttrTable & r = g_map_itemRare[i];

		if (r.dwApplyIndex != 0 && r.bMaxLevelBySet[nAttrSet] > 0 && HasRareAttr(i) != true)
		{
			avail.push_back(i);
		}
	}

	const TItemAttrTable& r = g_map_itemRare[avail[number(0, avail.size() - 1)]];
	int nAttrLevel = 5;

	if (nAttrLevel > r.bMaxLevelBySet[nAttrSet])
		nAttrLevel = r.bMaxLevelBySet[nAttrSet];

	attr.bType = r.dwApplyIndex;
	attr.sValue = r.lValues[nAttrLevel - 1];

	UpdatePacket();

	Save();

	const char * pszIP = NULL;

	if (GetOwner() && GetOwner()->GetDesc())
		pszIP = GetOwner()->GetDesc()->GetHostName();

	LogManager::instance().ItemLog(pos, attr.bType, attr.sValue, GetID(), "SET_RARE", "", pszIP ? pszIP : "", GetOriginalVnum());
	return true;
}

Thanks for every idea