Call JS variables and functions from C#??

Hi,

I download that: http://www.41post.com/1935/programming/unity3d-js-cs-or-cs-js-access

And the example works... So, I created a new project, and I create a new folder call Standard Assets on the Assets folder, and I created a new file call JSTest, and outside another file CSTest...

In the CSTest:

 using UnityEngine;
 using System.Collections;
 
 public class CSTest : MonoBehaviour {
 
     private JSTest Tester;
 
     // Use this for initialization
     void Start () {
         Tester = this.GetComponent<JSTest>();
     }
     
     // Update is called once per frame
     void Update () {
     
     }
 }

But inmediatly the JSTest turns red (because it wasn't found), and the following warning appear:

 Assets/CSTest.cs(6,24): warning CS0414: The private field `CSTest.Tester' is assigned but its value is never used

What can I do??

Thanks in advance. Bye.