how to get a bullet with a tag to collide with a wall

[system]

hey i used the tornadotwins tutorial and i need the fire ball with a tag to hit a wall how do i do this

[system]

use this script to delete the bullet object

function OnTriggerEnter( hit : Collider)

{

if(hit.gameObject.tag == "enemyProjectile") { Destroy(hit.gameObject); } }