Set only one child object visible

Hi everyone,

This is my first question on these boards.

I have a scene for a RTS game that is filled with units (just basic capsules). When I click a unit I wan't to set a plane visible that is attached as a child to the unit. All the child objects have the same name ("Plane"). The problem is when I select one unit all of the planes become visible.

The code:

 #pragma strict
 
 var selectedUnits = new Array();
 var isSelected = false;
 var target : Vector3;
 private var selectableLayerMask = 1 << 9;    //Units
 private var walkableLayerMask = 1 << 10;    //Ground
 var hit : RaycastHit;
 
 function Start () {
 }
 
 function Update () {    
     if (Input.GetMouseButtonDown(0)) {
         if (Physics.Raycast(Camera.main.ScreenPointToRay(Input.mousePosition),hit,200,selectableLayerMask)) {
             Debug.Log("Clicked on a unit");
             Debug.Log(hit.collider.name);
             AddUnit(hit.collider.gameObject);
             isSelected = true;
         }
         else {
             Debug.Log("Clicked on the ground");
             ClearSelectionList();
         }
     }
     
     if (isSelected) {
         transform.Find("Plane").renderer.enabled = true;
     }
     
     
 }
 
 function AddUnit (unitToAdd : GameObject) {
     selectedUnits.Push(unitToAdd);
     GetComponent(MoveUnit).targetPosition = transform.position;
     //transform.Find("Plane").renderer.enabled = true;
 }
 
 function ClearSelectionList () {
     selectedUnits.Clear();
     transform.Find("Plane").renderer.enabled = false;
     isSelected = false;
 }

Can someone help me with this issue.

Thanks in advance.