i am trying to make my character exit the car, its almost done, i just need a help

i have an script for exiting the car, but i need to target the player so:

 var player : GameObject;
 function Update () {
     if (Input.GetButtonDown("Exit")) {
 player.SetActive (true);

then i want to, for example, gameobject "A" is tagged with "B", so it will automatically be the var player.

any help?