How not to show text when colecting all items?

I have 5 items in my level and when I collected one text show up on the screen. I would like for the text to appear when I collect the first 4 items of my level and no text when I collect the last one. How can I do this? Here is my code I have on my items.

using UnityEngine; using System.Collections;

public class Item : MonoBehaviour {

 //Variables for text output on screen and audio
 public GUIText TextOutput;
 public AudioClip SoundToPlay;
 
 //Variables for the item pieces
 public static int itemCounter = 0;
 
 
 
 //Code for when the player collides with an item to collect.
 void OnTriggerEnter (Collider other)
 {
     //When the Player enters the area
     if (other.tag == "Player")
     {
         //The audio will play
         AudioSource.PlayClipAtPoint (SoundToPlay, this.transform.position);
         
         //Text will appear on screen
         TextOutput.text = "Look around the town for more pieces!";
         
         //Will increase the item count by one
         itemCounter += 1;
         
         //Simulate collection by destroying the item
         Destroy (gameObject.transform.parent.gameObject);

     }
 
     
 }

}