MissingFieldException UnityEngine.GUITexture.width not found?

Not sure why I am getting this error... Am I using .width wrong? Should I be using pixelinset? sorry, still learning.

 @script ExecuteInEditMode()
 
 var hitPoints : int;
 var painSound : AudioClip;
 var die : AudioClip;
 var deadReplacement : Transform;
 var mySkin : GUISkin;
 var explShake : GameObject;
 private var radar : GameObject;
 private var maxHitPoints = 100;
 var healthBarOriginalWidth = 100;
 var healthBar : GUITexture;
 var damageTexture : Texture;
 private var time : float = 0.0;
 private var alpha : float;
 private var callFunction : boolean = false;
 
 function Start(){
     maxHitPoints = hitPoints;
     alpha = 0;
 }
 
 function Update(){
     if (time > 0){ 
         time -= Time.deltaTime;
     }
     alpha = time;
 }
 
 function PlayerDamage (damage : int) {
     if (hitPoints < 0.0)
         return;
 
         // Apply damage
         hitPoints -= damage;
         audio.PlayOneShot(painSound, 1.0 / audio.volume);
         time = 2.0;        
     
 
     // Are we dead?
     if (hitPoints <= 0.0)
         Die();
         
 healthBar.pixelInset.width = - healthBarOriginalWidth * (hitPoints/maxHitPoints);
 }
 
 //Picking up MedicKit
 function Medic (medic : int){
     
     hitPoints += medic;
     
     if(hitPoints > maxHitPoints)
     hitPoints = maxHitPoints;
 }
 
 function Die () {
     if(callFunction)
     return;
     callFunction = true;
     
     if (die && deadReplacement)
         AudioSource.PlayClipAtPoint(die, transform.position);
 
     // Disable all script behaviours (Essentially deactivating player control)
     var coms : Component[] = GetComponentsInChildren(MonoBehaviour);
     for (var b in coms) {
         var p : MonoBehaviour = b as MonoBehaviour;
         if (p)
             p.enabled = false;
     }
     // Disable all renderers
     var gos = GetComponentsInChildren(Renderer);
     for( var go : Renderer in gos){
         go.enabled = false;
 
     }
     if(radar != null){
         radar = gameObject.FindWithTag("Radar");
         radar.gameObject.SetActiveRecursively(false);
     }
     Instantiate(deadReplacement, transform.position, transform.rotation);
     yield WaitForSeconds(4.5);
     LevelLoadFade.FadeAndLoadLevel(Application.loadedLevel, Color.black, 2.0);
 }
 
 
 function OnGUI () {
     GUI.skin = mySkin;
     GUI.contentColor = Color.red;
     
     
     GUI.color = Color(1.0, 1.0, 1.0, alpha); //Color (r,g,b,a)
     GUI.DrawTexture(new Rect(0,0,Screen.width, Screen.height), damageTexture);
 }
 
 function Exploasion(){
     explShake.animation.Play("exploasion");
 }