i have error in script : local
 
	ERROR: faction\factionadmin_s.lua:507: attempt to index local 'maxrow' (a nil value)
 
function adminDutyStart()
	local result = mysql:query("SELECT id, name FROM factions WHERE type >= 2 ORDER BY id ASC")
	local max = mysql:query("SELECT id FROM duty_allowed ORDER BY id DESC LIMIT 0, 1")
	if (result) and max then
		dutyAllow = { }
		dutyAllowChanges = { }
		i = 0
		local maxrow = mysql:fetch_assoc(max)
		maxIndex = tonumber(maxrow.id) or 0
			
		while true do
			local row = mysql:fetch_assoc(result)
			if not row then break end
			table.insert(dutyAllow, { row.id, row.name, { --[[Duty information]] } })
			i = i+1
				
			local result1 = mysql:query("SELECT * FROM duty_allowed WHERE faction="..tonumber(row.id))
			if result1 then
				while true do
					local row1 = mysql:fetch_assoc(result1)
					if not row1 then break end
					table.insert(dutyAllow[i][3], { row1.id, tonumber(row1.itemID), row1.itemValue })
				end
			end
		end
		setElementData(resourceRoot, "maxIndex", maxIndex)
		setElementData(resourceRoot, "dutyAllowTable", dutyAllow)
		mysql:free_result(result)
		mysql:free_result(result1)
		mysql:free_result(max)
	else
		outputDebugString("[Factions] ERROR: Duty allow permissions failed.")
	end
end
addEventHandler("onResourceStart", resourceRoot, adminDutyStart)
	how i can fix that ?