Unkown Identifier: 'Manager' error when trying to use singletons

Alright, so I am trying to use singletons in place of static variables. I have my main script, singleton script and a manager script. I get the error shown in the title.

Main (JS):

 #pragma strict
 import System.Linq;
 
 var currentProjectile : Rigidbody;
 var launcher : Transform;
 var speed = 10.0;
 //TEXT
 var objText : UI.Text;
 var scaleText : UI.Text;
 public static var extensions = Manager.Instance.extensionHolder;
 public static var customs = Manager.Instance.customText;
 private var childrens = [];
 private var iterator = 0;
 private var rescaleFactor = 1.00;
 var objects : Rigidbody[];
 function Start () {
     objects = Resources.LoadAll("Blocks", Rigidbody).Cast.<Rigidbody>().ToArray();
     childrens = customs.GetComponentsInChildren(UI.Text);
 }
 
 function Update () {
     if(Input.GetKeyDown("q")){
         if(iterator+1 == objects.length){
             iterator = 0;
             currentProjectile = objects[iterator];
             objText.text = "Current Object: "+currentProjectile.gameObject.name;
         } else {
             iterator = iterator + 1;
             currentProjectile = objects[iterator];
             objText.text = "Current Object: "+currentProjectile.gameObject.name;
         }
     }
     if(Input.GetKeyDown("e")){
         // Instantiate the projectile at the position and rotation of this transform
         var clone : Rigidbody;
         clone = Instantiate(currentProjectile, launcher.position, launcher.rotation);
         clone.transform.localScale = new Vector3(rescaleFactor, rescaleFactor, rescaleFactor);
         clone.mass = clone.transform.localScale.x;
         // Give the cloned object an initial velocity along the current 
         // object's Z axis
         clone.velocity = transform.TransformDirection (Vector3.forward * speed);
     }
     if(Input.GetMouseButtonDown(1)){
         rescaleFactor = rescaleFactor + 0.25;
         scaleText.text = "Re-scale Factor: "+rescaleFactor;
     }
     if(Input.GetMouseButtonDown(0) && rescaleFactor != 0.25){
         rescaleFactor = rescaleFactor - 0.25;
         scaleText.text = "Re-scale Factor: "+rescaleFactor;
     }
 }
 
 function resText() {
     objText.text = "Current Object: "+currentProjectile.gameObject.name;
     scaleText.text = "Re-scale Factor: "+rescaleFactor;
     for (var child : UI.Text in childrens) {
      child.text = "(unused)";
     }
 }

Singleton(This script was borrowed and in C#):

 using UnityEngine;
 
 /// <summary>
 /// Be aware this will not prevent a non singleton constructor
 ///   such as `T myT = new T();`
 /// To prevent that, add `protected T () {}` to your singleton class.
 /// 
 /// As a note, this is made as MonoBehaviour because we need Coroutines.
 /// </summary>
 public class Singleton<T> : MonoBehaviour where T : MonoBehaviour
 {
     private static T _instance;
 
     private static object _lock = new object();
 
     public static T Instance
     {
         get
         {
             if (applicationIsQuitting)
             {
                 Debug.LogWarning("[Singleton] Instance '" + typeof(T) +
                     "' already destroyed on application quit." +
                     " Won't create again - returning null.");
                 return null;
             }
 
             lock (_lock)
             {
                 if (_instance == null)
                 {
                     _instance = (T)FindObjectOfType(typeof(T));
 
                     if (FindObjectsOfType(typeof(T)).Length > 1)
                     {
                         Debug.LogError("[Singleton] Something went really wrong " +
                             " - there should never be more than 1 singleton!" +
                             " Reopening the scene might fix it.");
                         return _instance;
                     }
 
                     if (_instance == null)
                     {
                         GameObject singleton = new GameObject();
                         _instance = singleton.AddComponent<T>();
                         singleton.name = "(singleton) " + typeof(T).ToString();
 
                         DontDestroyOnLoad(singleton);
 
                         Debug.Log("[Singleton] An instance of " + typeof(T) +
                             " is needed in the scene, so '" + singleton +
                             "' was created with DontDestroyOnLoad.");
                     }
                     else
                     {
                         Debug.Log("[Singleton] Using instance already created: " +
                             _instance.gameObject.name);
                     }
                 }
 
                 return _instance;
             }
         }
     }
 
     private static bool applicationIsQuitting = false;
     /// <summary>
     /// When Unity quits, it destroys objects in a random order.
     /// In principle, a Singleton is only destroyed when application quits.
     /// If any script calls Instance after it have been destroyed, 
     ///   it will create a buggy ghost object that will stay on the Editor scene
     ///   even after stopping playing the Application. Really bad!
     /// So, this was made to be sure we're not creating that buggy ghost object.
     /// </summary>
     public void OnDestroy()
     {
         applicationIsQuitting = true;
     }
 }
 Manager (C#):
 using UnityEngine;
 using System.Collections;
 
 public class Manager : Singleton<Manager>
 {
     public string myGlobalVar = "whatever";
     public GameObject extensionHolder ;
     public GameObject customText ;
 }