Sphere is not colliding against Base???

Hey guys i created a sphere and generated the sphere colliders , while base is a scaled square … it has a box collder … but when run the game my sphere is passing through the plane … well , i attached the following script coz i was playing wid da vectors … as i start the game my sphere which is the target is changing it’s position .

#pragma strict
var target : Rigidbody;
private var Dir : Vector3 ;
private var px : Vector3=  Vector3(2,2,2);
function Update () 
{

if(Input.GetMouseButtonDown(0))
{
Dir.y = target.position.y + px.y;
}
if(Input.GetMouseButtonDown(1))
{
Dir.y = target.position.y - px.y;
}
target.position = Dir;

}

The problem is that Dir.x and Dir.z are uninitialized. Add the following line to the top of Update() or to the top of Start() depending on where you are going with your code:

Dir = transform.position;

resolved it on my own … the transformation was directly in the update function so i did the problem … placing the code into the id loops solved my problem.