How to refresh the view ?

Here is the code for a sphere :

 #pragma strict
 
 var distance_to_screen : float;
 var pos_move : Vector3;
 
 function OnMouseDrag()
 {
     distance_to_screen = Camera.main.WorldToScreenPoint(gameObject.transform.position).z;
     pos_move = Camera.main.ScreenToWorldPoint(new Vector3(Input.mousePosition.x, Input.mousePosition.y, distance_to_screen ));
     transform.position = new Vector3( pos_move.x, pos_move.y, pos_move.z );
 }
 
 function Update()
 {
    var hit:RaycastHit;
    var ray = Camera.main.ScreenPointToRay(Input.mousePosition);
    
     if (Input.GetMouseButton(0) && Physics.Raycast( ray, hit, 200 ))
     {
          hit.transform.localScale.x+=Input.GetAxis("Mouse ScrollWheel")* Time.deltaTime*20;
          transform.localScale.y=transform.localScale.z=transform.localScale.x;
     }
 }
 
 function Start () {
 
 }
 

The problem is when I transform the position or the scale of my sphere using my mouse, the old view of this sphere stays on the screen. Here is an image of the view when I move my sphere. I tried to solve this problem with SceneView.RepaintAll(); but it doesn't work.

Thank you

[1]: /storage/temp/67458-unity.jpg