my gun is on my fps conntroller but wont follow my mouse, the gun stays in front, instead of looking down with me it says out front, in front

pragma strict

function Update () {

 if(Input.GetButtonDown("Fire2")) {
 
     transform.localPosition = Vector3(0,0.518,0.808);
 }

 if(Input.GetButtonUp("Fire2")) {
 
     transform.localPosition = Vector3(0.543,0.331,0.832);
 }

}

this is my only script right now, is this effecting the aim, its for aiming down sights