how do i destroy a spawned object

first off all sorry for my english i’m dutch and can’t speak english that well

also i’m new to unity

click here to see picture

what i want is to have a box collider and when i step in it it spawns an gameobject.

i already have that
but now i need another box collider that will destroy that same object.

this is my code

#pragma strict

var Blokkade : GameObject;
var spawnposition;

function spawn_blokkade  ()
{
spawnposition = Vector3(0,0,-50);
var temp_spawn_blokkade = Instantiate(Blokkade, spawnposition, Quaternion.identity);
}



function OnTriggerExit(o:Collider){
spawn_blokkade();
}

function OnTriggerEnter(o:Collider){

}

Attach a script with this:

function OnTriggerEnter(other:Collider){

    Destroy(other.gameObject);

}

On the object that is to destroy the game object.