Throwing a ball around

Hi all, Here's my problem :

I'm using the FPS Character controller and i've attached an empty object called BallHolder (héhéhé i know!) and the ball is the children of it. When I click the mouse the ball object is released and should be throw.

Here's my code :

 var ballModel:Transform;
 var parentModel:Transform;
 var ballInPlay:boolean = false;
 var ballPower:float = 2000.0;
 
 function Update () 
 {
     controlBall();
 }
 
 function controlBall():void
 {
     if(Input.GetMouseButtonDown(0))
     {
         if(!ballInPlay)
         {
             ballModel.rigidbody.isKinematic = false;
             ballModel.rigidbody.AddForce(parentModel.Vector3.foward * ballPower);
             parentModel.DetachChildren();
         }
         
     }
 }

My main problem is with the AddForce sentence. If I just put a Vector3 in there it's works but since the player is rotating around, the ball goes only in the direction specified by the Vector3. But if I add the foward Vector3 I got this message from Unity :

MissingMethodException: Method not found: 'UnityEngine.Transform.Vector3'. NullReferenceException: Object reference not set to an instance of an object

Boo.Lang.Runtime.RuntimeServices.GetDispatcher (System.Object target, System.String cacheKeyName, System.Type[] cacheKeyTypes,)

I don't understand! Everything is nice in the editor, the transform are nicely put there.