Phaser Fullscreen icon and function

function fscreen(){
  game.scale.fullScreenScaleMode = Phaser.ScaleManager.SHOW_ALL;
  game.scale.startFullScreen();
}

function fsIcon(icon){
  var graphics = game.add.graphics(icon.x, icon.y);
  // draw a rectangle
  graphics.lineStyle(2, 0xFFFFFF, 1);
  var fsicon = graphics.drawRect(0, 0, 25, 25);
  game.input.onDown.add(fscreen, fsicon);
  return fsicon;
}