Lua Damage over time?

[Mc Lovin]

How can I make a spell give the target a poisoned effect that does specific damage every certain amount of seconds for an amount of time?

 

[JDB]

Soul Fire - Fire Damage

local combat = createCombatObject()
setCombatParam(combat, COMBAT_PARAM_TARGETCASTERORTOPMOST, true)
[COLOR="blue"]setCombatParam(combat, COMBAT_PARAM_TYPE, COMBAT_FIREDAMAGE)
setCombatParam(combat, COMBAT_PARAM_EFFECT, CONST_ME_HITBYFIRE)
setCombatParam(combat, COMBAT_PARAM_DISTANCEEFFECT, CONST_ANI_FIRE)[/COLOR]

local condition = createConditionObject(CONDITION_FIRE)
setConditionParam(condition, CONDITION_PARAM_DELAYED, 1)
[COLOR="red"][B]addDamageCondition(condition, 10, 2000, -10)[/B][/COLOR]
setCombatCondition(combat, condition)

function onCastSpell(cid, var)
	return doCombat(cid, combat, var)
end

These number's in red are how long, how many times, etc...