lerp Issue

var endPosition : Vector3 =Vector3 (0.0, 0.5, -5);
var lerpSpeed : float = 1.0;
private var startPosition : Vector3;

function Start () {
	startPosition = transform.position;
}

function Update () {
	transform.position = Vector3.Lerp(startPosition, endPosition, lerpSpeed * Time.deltaTime);
}