Unity 5 returns strange errors when compiling JavaScript code

Hello! Please help! I have successfully made a level with a Terrain, a Rigidbody FPS Controller from Standard Assets → Characters and some other GameObjects. I needed a saving system - so I have started to google file implementations in JavaScript. I have found some examples - but it returns compiler errors!

OS is Windows 10 64-bit. Unity version is 5.5.1f1 64-bit. Code editor is Visual Studio 2015, line endings corrected to Windows line endings. Language is JavaScript (UnityScript). Code I have used:

#pragma strict

import System;
import System.IO;

var Filename : String = "save.ini";
private var rwfile;

var x;
var y;
var z;

var Player : GameObject;

private var startTime : int;
private var timer1 : int;

function TimerSet() {startTime = Time.time;}

function TimerUpdate() {
    timer1 = Time.time;
    if(timer1 > 60) {
        Debug.Log("Saving");
        Write();
        TimerSet();}}

function WriterSetup() {
    Debug.Log("File Writer setup...");
    if (!File.Exists(Filename)) {
        rwfile = File.CreateText(Filename);}
    rwfile = OpenText(Filename);
    Debug.Log("File Writer configured sucsessfully");}

function Write() {
    rwfile.open("w");
    x = Player.transform.position.x;
    y = Player.transform.position.y;
    z = Player.transform.position.z;
    rwfile.WriteLine(x);
    rwfile.WriteLine(y);
    rwfile.WriteLine(z);
    rwfile.close();}

function Start() {Debug.Log("Saver Script Setup");
    WriterSetup();
    TimerSet();}

function Update () {TimerUpdate();}

Click here to see my compiling errors in a bigger size

I have already solved this on Stack Overflow, thanks CNuts!
Full working code:

#pragma strict

import System;
import System.IO;

var Filename : String = "save.ini";
private var rwfile : StreamWriter;
var x;
var y;
var z;
var Player : GameObject;

private var startTime : int;
private var timer1 : int;

function TimerSet() {startTime = Time.time;}

function TimerUpdate() {
    timer1 = Time.time;
    if(timer1 > 60) {
        Debug.Log("Saving");
        Write();
        TimerSet();}}

function WriterSetup() {
    Debug.Log("File Writer setup...");
    if (!File.Exists(Filename)) {
        rwfile = File.CreateText(Filename);}
    Debug.Log("File Writer configured sucsessfully");}

function Write() {
    rwfile = File.CreateText(Filename);
    x = Player.transform.position.x;
    y = Player.transform.position.y;
    z = Player.transform.position.z;
    rwfile.WriteLine(x);
    rwfile.WriteLine(y);
    rwfile.WriteLine(z);
    rwfile.Close();}

function Start() {Debug.Log("Saver Script Setup");
    WriterSetup();
    TimerSet();}

function Update() {TimerUpdate();}