Dodge System OTX 3.1

[Wanheda]

Hello, someone would have to make available some dodge system, where he defends% of the damage received.

I have a system, but it is not working, if someone can help me to correct the problem.

function onHealthChange(creature, attacker, primaryDamage, primaryType, secondaryDamage, secondaryType, origin)
    if not isPlayer(creature) then return false end
    if (creature:getDodgeLevel() * 3) >= math.random (0, 1000) and isCreature(attacker) then
        if isInArray({ORIGIN_MELEE, ORIGIN_RANGED, ORIGIN_SPELL}, origin) and primaryType ~= COMBAT_HEALING then
            primaryDamage = primaryDamage - math.ceil(primaryDamage * DODGE.PERCENT)
            creature:say("DODGE!", TALKTYPE_MONSTER_SAY)
            creature:getPosition():sendMagicEffect(CONST_ME_BLOCKHIT)
        end
    end
    return primaryDamage, primaryType, secondaryDamage, secondaryType
end