Help on attach to mouse script

Unity Engine
1

Hello all, I have been trying to get this script to work but I am pretty sure I am writing it wrong because it isn’t working. Basically it attached a gameObject (in this case a sphere) to the mouse so when I move the mouse it follows it. If you could tell me how to fix this and maybe show an example or give some tips it will be greatly appreciated. Here’s the script:

var ball : GameObject

function Start () {

Instantiate(ball);

}

function Update () {

GameObject.Find(ball), Camera.ScreenToWorldPoint(Input.mousePosition);

}

Thank you:)

2 
var ball : GameObject;

function Update ()
{
  var p : Vector3 = Camera.ScreenToWorldPoint(Input.mousePosition);
  ball.transform.position = p;
}

Something like that maybe.

3

I tried this and it dosnt work either:( All i the things seem like what you would need though so maybe its written in the wrong order? If you could give some advice on how to fix this that would be great.

Thanks