Key script not working right!

When I try to pick up a key in this script it doesnt.

The error is:

MissingMethodException: UnityEngine.GameObject.BackToNormal Boo.Lang.Runtime.DynamicDispatching.MethodDispatcherFactory.ProduceExtensionDispatcher () Boo.Lang.Runtime.DynamicDispatching.MethodDispatcherFactory.Create () Boo.Lang.Runtime.RuntimeServices.DoCreateMethodDispatcher (System.Object target, System.Type targetType, System.String name, System.Object[] args) Boo.Lang.Runtime.RuntimeServices.CreateMethodDispatcher (System.Object target, System.String name, System.Object[] args) Boo.Lang.Runtime.RuntimeServices+c_AnonStorey15.<>m_9 () Boo.Lang.Runtime.DynamicDispatching.DispatcherCache.Get (Boo.Lang.Runtime.DynamicDispatching.DispatcherKey key, Boo.Lang.Runtime.DynamicDispatching.DispatcherFactory factory) Boo.Lang.Runtime.RuntimeServices.GetDispatcher (System.Object target, System.String cacheKeyName, System.Type[] cacheKeyTypes, Boo.Lang.Runtime.DynamicDispatching.DispatcherFactory factory) Boo.Lang.Runtime.RuntimeServices.GetDispatcher (System.Object target, System.Object[] args, System.String cacheKeyName, Boo.Lang.Runtime.DynamicDispatching.DispatcherFactory factory) Boo.Lang.Runtime.RuntimeServices.Invoke (System.Object target, System.String name, System.Object[] args) UnityScript.Lang.UnityRuntimeServices.Invoke (System.Object target, System.String name, System.Object[] args, System.Type scriptBaseType) Key.Update () (at Assets/Key.js:51)

And:

MissingMethodException: UnityEngine.GameObject.TextureChange Boo.Lang.Runtime.DynamicDispatching.MethodDispatcherFactory.ProduceExtensionDispatcher () Boo.Lang.Runtime.DynamicDispatching.MethodDispatcherFactory.Create () Boo.Lang.Runtime.RuntimeServices.DoCreateMethodDispatcher (System.Object target, System.Type targetType, System.String name, System.Object[] args) Boo.Lang.Runtime.RuntimeServices.CreateMethodDispatcher (System.Object target, System.String name, System.Object[] args) Boo.Lang.Runtime.RuntimeServices+c_AnonStorey15.<>m_9 () Boo.Lang.Runtime.DynamicDispatching.DispatcherCache.Get (Boo.Lang.Runtime.DynamicDispatching.DispatcherKey key, Boo.Lang.Runtime.DynamicDispatching.DispatcherFactory factory) Boo.Lang.Runtime.RuntimeServices.GetDispatcher (System.Object target, System.String cacheKeyName, System.Type[] cacheKeyTypes, Boo.Lang.Runtime.DynamicDispatching.DispatcherFactory factory) Boo.Lang.Runtime.RuntimeServices.GetDispatcher (System.Object target, System.Object[] args, System.String cacheKeyName, Boo.Lang.Runtime.DynamicDispatching.DispatcherFactory factory) Boo.Lang.Runtime.RuntimeServices.Invoke (System.Object target, System.String name, System.Object[] args) UnityScript.Lang.UnityRuntimeServices.Invoke (System.Object target, System.String name, System.Object[] args, System.Type scriptBaseType) Key.Update () (at Assets/Key.js:34)

The code is in three parts the key script (obviously), the Cross-Hair and finally the door.

The Key Script:

 var Length : float = 3;
  
 static var HaveKey : boolean = false;
 var ShowText : boolean = false;
  
 var Text : String = "You picked up a key";
 
 var FirstPersonController = GameObject;
 
 var Crosshair = FirstPersonController;
  
 var other : GameObject;
  
 function Update () {
  
 var hit : RaycastHit;
        
 var ray : Ray = camera.ViewportPointToRay (Vector3(0.5,0.5,0));
        
 var fwd = transform.TransformDirection (Vector3.forward);
  
 Debug.DrawRay(transform.position, fwd * Length, Color.green);
        
         if(Physics.Raycast(ray, hit, Length))
  
         {      
                
                 hitObject = hit.collider.gameObject;
                
                 if(hitObject.gameObject.tag == "Key")
  
                         {
                
                                 other.GetComponent(Crosshair).TextureChange();
                
                                 if(Input.GetKeyUp(KeyCode.E))
                                 {
                        
                                         GetKey();
                                         Destroy(hitObject);
                                        
                        
                                 }
                                
                                
                         }
                
                         else if(hitObject.gameObject.tag == "Untagged")
                
                         {
                                 other.GetComponent(Crosshair).BackToNormal();
                         }
  
                 }
        
         else if(!Physics.Raycast(transform.position, transform.forward, hit, Length))
         {
                 other.GetComponent(Crosshair).BackToNormal();
         }
        
        
  
 }
  
 function GetKey(){
  
         HaveKey = true;
  
         ShowText = true;
        
         yield WaitForSeconds(3);
        
         ShowText = false;
 }
  
 function OnGUI(){
  
 if(ShowText)
 {
         GUI.Label(Rect(Screen.width /2 -62.5, Screen.height /2 + 50, 200, 100), Text);
 }
  
 }

THE CROSS-HAIR SCRIPT:

 var CrosshairTexture : Texture2D;
  
 var UseTexture : Texture2D;
  
 var NormalTexture : Texture2D;
      
 var ShowCrosshair : boolean = true;
  
 var CanChange : boolean = false;
          
 function Start()
 {      
         Screen.lockCursor = true;
 }
          
 function OnGUI()
 {
         if(ShowCrosshair == true)
         {
         GUI.Label(Rect((Screen.width - CrosshairTexture.width) /2, (Screen.height -
                         CrosshairTexture.height) /2, CrosshairTexture.width, CrosshairTexture.height), CrosshairTexture);
         }
  
 }
  
  
 function OnTriggerEnter(other : Collider)
 {
         if(other.gameObject.tag == "Door")
         {
                 CanChange = false;
        
                 CrosshairTexture = UseTexture;
        
         }
  
 }
  
 function OnTriggerExit(other : Collider)
 {
         if(other.gameObject.tag == "Door")
         {
                 CanChange = true;
        
                 CrosshairTexture = NormalTexture;
                
                
         }
  
 }
  
 function TextureChange(){
  
 if(!CanChange)
 {
  
 CrosshairTexture = UseTexture;
  
 CanChange = true;
  
 }
  
 }
  
 function BackToNormal(){
  
 if(CanChange)
 {
  
 CanChange = false;
  
 CrosshairTexture = NormalTexture;
 }
  
 }

LOCKED DOOR SCRIPT:

 var IsOpen : boolean = false;
  
 var CanOpen : boolean = false;
  
 var NeedKey : boolean = true;
  
 //Audios:
  
 var Locked : AudioClip;
  
 var Open : AudioClip;
  
 //Other:
  
 var Volume : float = 0.5;
  
 var KeyScript : GameObject;
  
  
  
  
 function Start () {
 audio.volume = Volume;
 }
  
 function Update () {
  
  
 if(Input.GetKeyUp(KeyCode.E) && !IsOpen && CanOpen && !NeedKey)
  
 {
         Opening();
         IsOpen = true;
         audio.clip = Open;
        
         audio.Play();
 }
  
 else if(Input.GetKeyUp(KeyCode.E) && IsOpen && CanOpen && !NeedKey)
  
 {
         Closing();
         IsOpen = false;
 }
  
 else if(Input.GetKeyUp(KeyCode.E) && CanOpen && NeedKey)
  
 {
         audio.clip = Locked;
        
         audio.Play();
 }
  
 if(KeyScript.GetComponent(Key).HaveKey == true)
 {
         NeedKey = false;
 }
  
 }
  
  
  
 function Opening()
 {
 for (var i = 0; i < 100; i++)
 {
     transform.Rotate(0,0.9,0);
    
     yield WaitForSeconds(0.01);
         }
 }
  
 function Closing()
 {
 for (var i = 0; i < 100; i++)
 {
     transform.Rotate(0,-0.9,0);
    
     yield WaitForSeconds(0.01);
     audio.clip = Open;
        
         audio.Play();
         }
 }
  
 function OnTriggerEnter (other : Collider)
 {
         if(other.gameObject.tag == "Player")
         {
                 CanOpen = true;
         }
 }
  
 function OnTriggerExit (other : Collider)
 {
         if(other.gameObject.tag == "Player")
         {
                 CanOpen = false;
         }
 }
  
  
  
  
  
 @script RequireComponent(AudioSource)

PLEASE HELP IF YOU CAN! ALSO I FORGOT TO MENTION THAT: BackToNormal and TextureChange Are functions.