Newbie scripting question(?)

Im trying to make a status effect spell with triggers, but I can't figure out how to make the effects of the trigger remove themselves when the buff\spell is dispelled, or how to make the duration of the effects linked to the actual spell duration, can anyone help me with this?

OK say, for this trigger I want Lighting to strike all around the target unit over a period of time, and the units move speed decreased
We'll need 1 special effect variable named SpecialEffect001 and a unit variable named abilitytarget
And 1 region named region001
have the trigger like this

- Trigger1 -
Event
Unit Owned by (player) (Finishes Casting an Ability)
Condtion
Abilty equal to (Ability001)
Action
-Turn on (Trigger2)
Set (Target Unit Of Ability Being Cast) to (AbiltyTarget)
-Create a (Abilities\Spells\Other\Monsoon\MonsoonBoltTarget.mdl) at (origin) (AbiltyTarget)
-Set (Last Created Special Effect) to (SpecialEffect001)
-Set Unit Movement speed to (100)
-Change (AbiltyTarget) Animation speed to (50%)
-Move (Region001) To (Postion of Target)(Unit Of Ability Being Cast)
-Create a Special effect at (Random point in Region001) using (Abilities\Spells\Other\Monsoon\MonsoonBoltTarget.mdl)
-Wait 1 second
-Create a Special effect at (Random point in Region001) using (Abilities\Spells\Other\Monsoon\MonsoonBoltTarget.mdl)
-Turn off (Trigger2)

Have this continue for how ever long your duration is

Have another trigger that is off to start with that continues to move the region to the target of the spell

- Trigger 2 -
Event
Peridoic event every .1 second
Condtion
none
Action
Move (region001) to (Postion of)(AbiltyTarget)



i think this will work

Cool, thanks!