BCE0019: 'Add' is not a member of 'UnityEngine.Transform[]'

plz help >>>>>>

Assets/Wall/Walls.js(10,25): BCE0019: 'Add' is not a member of 'UnityEngine.Transform[]'

var wallpreba : Transform; var myArray : Transform[];

function Start () {

 var go : GameObject[] = GameObject.FindGameObjectsWithTag("wall");
 for (var wall : GameObject in go)
 {
     Instantiate(wallpreba, wall.transform.position, wallpreba.transform.rotation);
     myArray.Add(wall);
 }

}