问如何使用GUIText显示健康状况？

EN

using UnityEngine;
 using System.Collections;

 public class HealthScript : MonoBehaviour {

     public static HealthScript instance;
     public int hp = 1;
     private GUIText scoreReference;
     private GUIText highscoreReference;
     private static int _highscore = -1;
     public int highscore { 
         get { if (_highscore == -1) 
             _highscore = PlayerPrefs.GetInt("Highscore", 0);
             return _highscore; 
         }
         set {
             if (value > _highscore) {
                 _highscore = value;
                 highscoreReference.text = _highscore.ToString();
                 PlayerPrefs.SetInt("Highscore", _highscore);
             }
         }
     }

     public bool isEnemy = true;


     private static int points;
     public void Damage(int damageCount) {
         hp -= damageCount;

         if (hp <= 0)
         {
             // Dead!
             Destroy(gameObject);
             points++;
             scoreReference.text = points.ToString();
         }
     }

     public void gameEnd() {

         highscore = points;
         points = 0;
     }


     void Start()
     {
         scoreReference = GameObject.Find("Score").guiText;
         highscoreReference = GameObject.Find("HighScore").guiText;
         scoreReference.text = points.ToString(); 
         highscoreReference.text = highscore.ToString ();
         instance = this;
     }