AddForce/ForceMode.Impulse

Hey Unity Answers Users...

I'm here today with a script and a problem. I need to find a way to add force to a projectile fired at another object. I need it to be in a curve fashion (Catapult Effect).

Here is my script: #pragma strict

var sProjSpd : int;

var sProjDir : Vector3;

var targetP : GameObject;

function OnEnable()

{

 targetP = GameObject.FindGameObjectWithTag("targetP");

 sProjDir = Vector3.Normalize(this.transform.position);

}

function Update()

{
if(Input.GetKeyDown("space"))

 {
     transform.position = Vector3.MoveTowards(this.transform.position, targetP.transform.position, sProjSpd*Time.deltaTime);
 }

}

Any help would be great. I have dabbled in putting addforce and forcemode.impulse but they seem not to work.

Regards, Trent