Access object from script problem.

I have found many suggestions using google,
on how to access the object which your script
is attached to, but common for all of them are:
They do not work! Because it involves a “:” in
the initialization, which Unity won’t accept.

My question(s) are:

1a) Could this be a product of failure,
due to the fact I use the free version?

1b) …if not, can you access an object which
the script is attached to, without using “:”?

Just like this (As an example):

using UnityEngine;
using System.Collections;

public class YourScript : MonoBehaviour
  void Start(){
    gameObject.transform.position=new Vector3(0.2f,0.5f,0.3f);

  void Update(){
    float x = gameObject.transform.position.x;

    //do whatever you want with this x

    //since we can't change x directly, we have to do a workaround
    Vector3 LastPos = gameObject.transform.position;