var moveSpeed : float = 1f;  
  var changeTime : float = 1f;  
  var randomLimit : float = 0.25f;  
  var R: float = 1;
  private var tempPos : Vector2;  
  private var newPos : Vector3;  
  private var randomTime : float;  
  private var changeOrder : boolean = true;  

  function Update ()  
  {  
   if(shiftMode == false)
   {
        if (changeOrder)  
        {   
         changeOrder = false;
         ChangePosition();   
        }  
     }
  }  
  function ChangePosition ()  
  {  
           tempPos = Random.insideUnitCircle * R;    
           newPos = new Vector3(tempPos.x, tempPos.y, 0);  
           randomTime = Random.Range(-randomLimit, randomLimit);  
           yield WaitForSeconds(changeTime + randomTime);  
           changeOrder = true;  
  }