Resizing a tiledmap when using phaser

var cw = window.innerWidth;
        var ch = window.innerHeight;
        var game = new Phaser.Game(cw, ch, Phaser.AUTO, 'game', { preload: preload, create: create, update: update });

        function preload() {
            game.load.tilemap('Background', 'https://gist.githubusercontent.com/anonymous/c61b37df015a0b2af1d7/raw/172bf9c2d4c20c56699eacce263525409caaf743/54996634e4b0a35d00c9b516.json', null, Phaser.Tilemap.TILED_JSON);
            game.load.image('tiles', 'http://i.imgur.com/gmWQIFK.png');
            game.load.image('player', 'http://i.imgur.com/tCCrLyh.png');
        }

        var map;
        var layer;
        var player;
        var _keyboard;
        var playerJumping;
        function create() {
            player = game.add.sprite(0, ch - 32, 'player');
            game.world.setBounds(0, 0, cw, ch);
            game.physics.startSystem(Phaser.Physics.ARCADE);
            game.physics.arcade.gravity.y = 300;
            game.physics.enable(player, Phaser.Physics.ARCADE);
            player.body.collideWorldBounds = true;
            game.stage.backgroundColor = '#787878';
            map = game.add.tilemap('Background');
            map.addTilesetImage('smb_tiles', 'tiles');
            layer = map.createLayer('Tile Layer 1');
            layer.resizeWorld();

            _keyboard = game.input.keyboard.createCursorKeys();
            game.camera.follow(player);
        }
        function update()
        {
            player.body.x += 2;
            if (_keyboard.up.isDown && player.body.onFloor()) {
                playerJumping = true;
                player.body.velocity.y = -2;

            }
            else {
                playerJumping = false;
            }
        }

<script src="http://yourjavascript.com/222115941388/phaser-min.js"></script>
<div id="game"></div>