Make the object dissapear when not detected

I've been trying to edit a script i found that plays a sound when the target is found (and it works) , but i can't manage to do the following: make the object above the target dissapear when not detected ( so it doesn't stay on the screen after it's lost) 

using UnityEngine; using System.Collections; using Vuforia;

public class SunetSucces : MonoBehaviour, ITrackableEventHandler { private TrackableBehaviour mTrackableBehaviour;

void Start() {   mTrackableBehaviour = GetComponent<TrackableBehaviour>();   if (mTrackableBehaviour)   {    mTrackableBehaviour.RegisterTrackableEventHandler(this);   } }

public void OnTrackableStateChanged(   TrackableBehaviour.Status previousStatus,   TrackableBehaviour.Status newStatus) {   if (newStatus == TrackableBehaviour.Status.DETECTED ||    newStatus == TrackableBehaviour.Status.TRACKED ||    newStatus == TrackableBehaviour.Status.EXTENDED_TRACKED)   {    // Play audio when target is found    GetComponent<GameObject>().SetActive(true);   }   else   {    // Stop audio when target is lost    GetComponent<GameObject>().SetActive(false);   } }   }

And it doesn't work, so any ideas why? or do you have any other script like this? i'd rly apriciate it