code: function () {
  		var chart = this,
  			lang = defaultOptions.lang,
  			btnOptions = chart.options.chart.resetZoomButton,
  			theme = btnOptions.theme,
  			states = theme.states,
  			alignTo = btnOptions.relativeTo === 'chart' ? null : 'plotBox';
  			
  		this.resetZoomButton = chart.renderer.button(lang.resetZoom, null, null, function () { chart.zoomOut(); }, theme, states && states.hover)
  			.attr({
  				align: btnOptions.position.align,
  				title: lang.resetZoomTitle
  			})
  			.add()
  			.align(btnOptions.position, false, alignTo);
  			
  	}
docs: Display the zoom button