Can anyone help me with a simple JS wait problem

I´m trying to stop the movement of an object at its starting and end points The object ping-pongs from A to B

This is the code I´m using. this code is not mine btw

 var pointB : Vector3;
 
 function Start () { var pointA = transform.position; while (true) { yield MoveObject(transform, pointA, pointB, 3.0); yield MoveObject(transform, pointB, pointA, 3.0); } }
 
 function MoveObject 
 (thisTransform : Transform, startPos : Vector3, endPos : Vector3, time : float) 
 { 
 var i = 0.0; var rate = 1.0/time; 
 while (i < 1.0) 
 { i += Time.deltaTime * rate; thisTransform.position = Vector3.Lerp
 (startPos, endPos, i); yield;
 } 
 }

Thanks to anyone how can help me with this...